A Project Report on Cost Reduction in Melting- A SQC and Six Sigma Approach

COST REDUCTION IN MELTING- A SQC and SIX SIGMAAPPROACH Done at ARUNA ALLOY STEELS PVT.LTD A PROJECT REPORT Submitted by ` ARUN KUMAR.S (105914144005) In partial fulfillment for the award of the degree of BACHELOR OF ENGINEERING IN MECHANICAL ENGINEERING RAJA COLLEGE OF ENGINEERING AND TECHNOLOGY, MADURAI ANNA UNIVERSITY: CHENNAI 600 025 APRIL 2014 1 ANNA UNIVERSITY: CHENNAI 600 025 BONAFIDE CERTIFICATE Certified that this project report “COST REDUCTION IN MELTINGA SQC and SIX SIGMA APPROACH” is the bonafide work of “ARUN KUMAR.S (105914144005)”, who carried out the project work under my supervision. SIGNATURE SIGNATURE Prof. S. Saravana Kumar, B.E., M.E., J.Vivek, B.E., M.E., MBA., (Ph.D), HEAD OF THE DEPARTMENT SUPERVISOR Assistant professor Mechanical Engineering Mechanical Engineering Raja College of Engg&Tech, Raja College of Engg &Tech, Madurai- 625020. Madurai- 625020. Submitted for the project vice-voce held on …………… INTERNAL EXAMINER EXTERNAL EXAMINER 2 ACKNOWLEDGEMENT This project has been successfully completed owing comprehensive endurance of many distinguished persons. First and foremost I would like to thank the almighty, my family members and friends for encouraging me to do this project. I extend my thanks to Chairman PDG.Lion. G. Nagarajan, M.A and Principal Dr. S.M. Sekkilar, M.E., Ph.D., for their advice and ethics inculcated during the entire period of my study. I am extremely indebted to Prof. S. Saravana Kumar, B.E., M.E., MBA., (Ph.D)., The Head of Department of Mechanical Engineering for the devoted attention, love and affection shown on me in making this project grand success. I also thank the HR Mr.M.J.Ramachandran, MSW for his assistance and all those who have supported me to do the project in ARUNA ALLOY STEELS PVT.LTD., Madurai. I would like to thank my Company guide Mr.M.Raj Kumar, M.Tech Metallurgy, Assistant Manager- Metallurgy for his devoted attention and affection shown on me to do this project in a good manner. I profusely thank my internal guide Mr.J.Vivek, M.E., Asst. professor, Mechanical Engineering for his support throughout the project. His suggestions and participative encouragement throughout the project will ever hold a memorable place in my heart. Finally, I thank one and all for their valuable support in this project work. 3 ABSTRACT In ARUNA ALLOY STEELS PVT. the castings with raw materials as scraps and scraps + returns are taken and tested. weld repairs.LTD.. 4 . etc. Defects are reduced by implementation of Statistical Quality Control (SQC) technique and DMAIC Methodology of Six Sigma. shrinkage. inclusions. CK3MCuN Castings are rejected due the defects such as cracks. So . 4 products 16 16 1.3.4.TABLE OF CONTENTS CHAPTER NO TITLE PAGE NO.4.6 Plug valve 20 1.3 Ball valve 18 1.4.4.1 General introduction 1 1.4.3 Company profile 11 1.4.4 Globe valve 19 1.4.2 Butterfly valve 17 1. ABSTRACT iv LIST OF TABLES x LIST OF FIGURES xi 1 INTRODUCTION 1 1.1 Management team 1.7 Double plug valve 21 5 .1 Gate valve 16 1.5 Check valve 19 1.2 Industry profile 1 1. 6.6.8 Lower body 31 1.16 Gate casting 34 1.1.11 Trunion 33 1.6.13 Body tubing spool 33 1.9 Four way globe valve body 32 1.14 Pump casting 33 1.6.6.10 Iso pad 32 1.6.6 Ball valve 29 1.6.15 Agitator (outer & central) 34 1.6.8 Angle valve 22 1.6.6.6.2 Globe valve 26 1.12 Stem housing 33 1.17 Y-Body (weld neck) 34 1.5 Butterfly valve 29 1.18 Lock ring 34 6 .5 Grades of Steel 23 1.6 Critical dimensions of castings 24 1.1Gate valve 24 1.6.7 Angle valve 30 1.6.4.4 Plug valve 28 1.6.3 Check valve 27 1.6.6.6.6. 4 Melting 41 42 3.2.7 Fettling 45 3.2.6.1 Pattern making 38 3.1 Specimen Preparation 3.2.20 Body casting heads 35 LITERATURE REVIEW BASICS OF FOUNDRY 36 36 3.4.4.3 Moulding 41 3.6 Laboratory tests 45 3.2.3.8 Heat treatment 46 3.2 Processes of a foundry 38 3.2.19 Bracket 35 1.2.2.2.2.5 Pouring 44 3.2.1 Melting Techniques 43 3.2.10 Despatch & packing 7 47 47 .2.2.2.2 Induction Furnace 43 3.9 Quality control 3.1 Foundry 38 3.6.1 Pattern 39 3.2 Methoding 39 3.1.2 3 \ 1. 2 Testing methods 76 5.1 DMAIC methodology 70 METHODS OF MEASURING THE DEFECTS 5.4 Penetrant Testing 83 8 .4 3.2.1.2.1 Process inspection 76 5.1 Problem solving techniques 5 68 4.1 Statistical quality control 68 4.3 Dimensional inspection 76 5.3.1.2 Radiographic Testing 78 5.2.1.3 Non destructive testing [NDT] 77 5.1 Inspection of casting 76 76 5.3Ultrasonic Testing 82 5.3.3.2.2.3 Terms used in melting area of foundry 47 3.2.3.1.4 Metals used in a foundry 61 CASE STUDY 68 4.2 Six Sigma 69 4.2 Visual inspection 76 5.2.1.2 Destructive testing 76 5.1Magnetic Particle Inspection (MPI) 77 5.1 Pressure testing 76 5.1.2. 6 AVOIDING THE DEFECTS IN CASTING 84 ANNEXURE 87 REFERENCES 95 9 . 2.1.2.1.2.4 WCB castings with Scraps + Returns 73 Table 4.2 Production of Finished Carbon Steel (In Million Tonnes) Table 2.2.1.5 Cost analysis of CK3MCuN Castings With Scraps & Scraps + Returns Table 4.1.2 CK3MCuN castings with Scraps + Returns 72 Table 4.1 PAGE NO Apparent Consumption of Finished Steel (Carbon)(In million tonnes) Table 1.3.LIST OF TABLES Table 1.1 CK3MCuN castings with Scraps 72 Table 4.2.2.6 75 Cost analysis of WCB Castings With Scraps & Scraps + Returns 75 Table 5.3 WCB castings with Scraps 72 Table 4.1 2 7 Application of SIX SIGMA in Manufacturing Sector 37 Table 4.1.2.1.2.2 Selection of Radiation Sources 79 10 .1.2.2.2.1.1.1 Penetrating Power of Radiation 79 Table 5.1.1.3.1.2. LIST OF FIGURES Figure 1.1.1.2 RT NSD% of WCB castings with Scraps & Scraps + Returns 73 Figure 4.2.2.1 Double plug valve 21 Figure 1.1.2 Major consumer industries of steel in India 6 Figure 1.2.4.2.1 Globe valve 19 Figure 1.4.1 Fishbone diagram for defects in casting 71 Figure 4.1.3 RT NSD% of WCB castings with Scraps & Scraps + Returns 73 Figure 4.4.1.1.1 Ball valve 18 Figure 1.2.1 Check valve 20 Figure 1.4 RT NSD% of CK3MCuN castings with Scraps& 11 .4.4.4.2.8.1 Induction furnace 44 Figure 4.1 Gate valve 16 Figure 1.7.4.5.1.2.2.1 Angle valve 23 Figure 3.1- PAGE NO Apparent consumption of finished carbon steel (In Metric Tonnes) 3 Figure 1.2.1.6.4.1 Butterfly valve 17 Figure 1.3.4.4.1.1 Plug valve 21 Figure 1. 3.4.2.3.3.4 Iridium 192 Radiographic testing 80 Figure 5.1 Ultrasonic Testing 83 Figure5.2.2.3.2.2 Radiographic testing 79 Figure 5.Scraps + Returns 74 Figure 4.2.1 Radiographic testing 79 Figure 5.2.1.3.2.2.3.1 Magnetic particle inspection 77 Figure 5.1.3 Cobalt 60Radiographic testing 80 Figure 5.2.5 Weld% of CK3MCuN castings with Scraps& Scraps + Returns 74 Figure 5.2.2.1 Dye Penetrant Testing 83 CHAPTER 1 INTRODUCTION 12 .2.3.3.1.6 Radioactive Isotope Material 82 Figure 5.3.3.2.2.2.2.5 Penetrating Power of Radiation 81 Figure 5. 13 .1. Though the subprime crisis has lead many economies to recessionary trend.2 INDUSTRY PROFILE THE GLOBAL STEEL INDUSTRY The current global steel industry is in its best position compared to last decade. mining. However steel production and consumption will be supported by continuous economic growth. The shares of steel industries are also in a high pace. Melur road. the quality tools. Madurai625107. nickel based alloy steel.. Madurai. locomotive. and super duplex for different types of steel castings in various sizes and weights up to Kg per piece of oil and gas sector. alloy steels of various compositions. has been conducted as a part of Bachelor of Engineering in Mechanical Engineering of Anna University. causes. Tamil Nadu State. The price has been rising continuously. Ltd. Narasingampatti and Pudur of Madurai city. 1.”. stainless steel. power and other engineering industries. defects in casting. Tamil Nadu.1 GENERAL INTRODUCTION “A Project on the Quality Management and Cost Benefit Analysis of Steel Castings at ARUNA ALLOY STEELS Pvt. The project is mainly concentrated on the Melting and Quality Department. the negative effect has not touched the steel industry as a whole. effects and methods to reduce etc. ARUNA ALLOY STEELS Pvt. There is many more merger and acquisitions which overall buoyed the industry and showed some good results. The company manufactures steel castings of carbon steel. is a leading steel manufacturing unit with foundries situated in Olaganeri. The demand expectations for steel products are rapidly growing for coming years. covering the foundry functioning. Ltd. Olaganeri. infrastructure and housing. steel. We expect strong demand growth in India over the next five years. Table 1. steel. coal and cement) industries of India.84 1992-1993 15 1. Finished (carbon) Steel production registered a robust growth of 9. The steel industry in India has been moving from strength to strength and according to the Annual Report 2009-10 by the Ministry of Steel.STRUCTURE OF INDIAN STEEL INDUSTRY Steel is one of the six core (power.3 MT in the 12 months to March 2010 from 52.in) YEAR DEMAND( in m t) GROWTH( in %) 1991-1992 14.1 Apparent Consumption of Finished Steel (Carbon) (In million tonnes) (Government of India. has put India's steel industry on the world steel map.32 2.3 MT in the year 2009. at home and abroad. real estate and automobiles.2% in March compared to 3. India has emerged as the fifth largest producer of steel in the world and is likely to become the second largest producer of crude steel by 2015-16. Soaring demand by sectors like infrastructure.7% in the index of industrial production which grew 7. Ministry of Steel. over the same period of 2009 on account of improved demand from sectors like automobile. as per the Ministry of Steel. CONSUMPTION OF STEEL IN INDIA India's steel consumption rose 8 per cent in the year ended March 2010.2% in March 2010 compared to a negative growth of 1. These six core industries that have a combined weightage of 26.07 1993-1994 15.3% in the same period 2009. The country’s steel consumption increased to 56. driven by a boom in construction (43% plus of steel demand in India).8% in March 2009. petroleum refining.nic.2. petroleum crude.13 14 . 389 10.2.21 1997-1998 22.84 2008-2009 54.35 1.65 2003-2004 31.61 FIGURE 1.15 2.1994-1995 18.169 7.43 2001-2002 27.80 1995-1996 21.66 21.833 -0.29 1999-2000 25.777 30.01 8.30 1998-1999 23.86 2004-2005 34.12 3.47 2007-2008 55.93 2006-2007 49.63 2.84 1996-1997 22.03 2000-2001 26.33 2005-2006 38.APPARENT CONSUMPTION OF FINISHED CARBON STEEL (IN METRIC TONNES) 15 .87 7.174 10.1.43 14.897 5.78 2002-2003 28.151 10. 2010) . The industry is one of the key drivers of India’s economic growth. In fact. Strong population growth. The Indian office market is benefiting from the ongoing off shoring activities of industrial nations. opening of the economy and rising investment. Their second main business area is assuming the responsibility for entire support processes. Up to 10 million new homes need to be built each year until 2030. per-capita GDP – in purchasing power parity terms – should rise by nearly 4% per year until 2020. Indian insurers are concentrated in the software development and software product segments. In addition to the sports facilities.The growth drivers are population growth. by the end of the decade India could replace Japan as the world’s third biggest economy after the US and China. International rating agency Fitch Ratings has forecast an 8% growth in India's GDP in 2010-11 with the industries and services being the primary drivers (DNA May 10.MAJOR CONSUMERS OF INDIAN STEEL INDUSTRY: Support from dynamic economy: India is the economic region that has enjoyed the world’s most sustained boom. or business process outsourcing (BPO). the Ministry for Urban Development and Poverty Alleviation claims that no less than 31 million dwellings are needed. Positive stimuli from construction industry: The steel companies are pinning their hopes largely on the expanding construction industry. The hosting of the Commonwealth Games in New Delhi in 2010 generated additional stimulus for the construction industry and thus boost demand for steel. These segments 16 . rising incomes and decreasing household sizes are forcing comprehensive measures to be taken in the housing sector. Despite the sharp increase in India’s population. The pent-up demand for housing is estimated at around 20 million units by the Indian Construction Association. human capital. accommodation for competitors and visitors was planned. Furthermore. Germany claims a particularly large share of Indian imports of Woodworking machinery and machine tools as well as pumps and compressors. firms have to make numerous investments in modernising and expanding their machinery portfolios Makers of building machinery are benefiting from the large-scale infrastructure projects planned by the Indian government. while import growth is slightly crimped. In India a small but flourishing automobile industry has now developed that sees its future primarily in the budget price segment and views the domestic market and other emerging nations as potential markets. By comparison. but its growth rate is the highest of the most important clients for the steel industry. Since the domestic textile and apparel industry. Capital expenditure is to be focused on road building and the rail network. while machine-tool makers are being buoyed by the upturn in the automobile and auto parts industries for example. Thanks to the march of technological progress the prospects for domestic suppliers should improve going forward. including machinery to the value of about USD 1 bn to India. Exports by the Indian mechanical engineering industry rose recently by nearly 30% to USD 10 bn. for example. Booming automobile industry: The automotive industry may consume a relatively small proportion of steel output. is focusing further up the value chain. as well as on the construction and expansion of ports and airports. The demand for foreign machinery comes from customers requiring especially high standards of performance and precision. over the past five years. Strong growth in mechanical engineering: Mechanical engineering output has increased some 10% p.still look set for growth. 17 . the construction sector is benefiting from major infrastructure projects.a. German mechanical engineering firms exported products worth close to USD 117 bn. Demand is greatest for building machinery and plasticmoulding machines as well as machine tools and textile machinery. The growth of the Indian automobile industry is being driven by healthy domestic demand. and Ford manufactures vehicles there for South Africa and other markets. Whereas in 1995 there were just five carmakers in India the figure has now reached 10. uses the country as an export base for small cars.000 cars each year (Germany: 5. The Tata group is even trying to gain a foothold in the European market with new models. India currently produces a total of 711.2. FIGURE 1. The consumption minded.000 inhabitants are even less widespread than in China with its very low figure of 21. it is not uncommon for cars to be used for 20 years (Western Europe: 12 years).Vehicle ownership (cars and trucks) in India at 11 per 1. The population’s steadily growing demand for mobility and sharply rising traffic volumes will continue to generate strong demand for cars in the future.4 million).2 – MAJOR CONSUMER INDUSTRIES OF STEEL IN INDIA 18 . competition between automakers has intensified markedly. for example. with vehicles that have been taken off urban roads often being driven for longer in rural areas. fast growing middle class is a major factor. At the same time India’s automobile sector is establishing itself as an exporter to international markets. Hyundai. The continuing increase in incomes and low-cost financing facilities are boosting sales. However. However. The biggest are Hyundai Motor India and Tata Engineering (Telco). the world’s biggest steelmaker. production volumes fell in the US and the EU-25 by nearly 5% and roughly 4% respectively. Table 1. between 2000 and 2005).SUPPLY OF STEEL IN THE INDIAN MARKET Over the past ten years India’s crude steel output rose nearly 7%per year to 55. The growth drivers are the expanding client industries.a.3 million tons .a.a.2 .a. Mechanical engineering (up 10% p. produces nearly ten times as much as India. The entire industry’s contribution to gross domestic product should rise in the coming years to more than 30% – compared to just fewer than 27% at present.5 million tons was 8%higher than in 2004. while global crude steel output increased by 4% (Germany managed an increase of just under 1%p.Production of Finished Carbon Steel (In Million Tonnes) 19 .2. In 2005 India’s crude steel output of 46. it is roughly the same as Ukraine’s share of world steel production. By contrast. China.).) Although India is the world’s eighth largest steel producer.) and construction (up 6% p. only in China was the growth rate considerably higher at 15%. its3%-plus share of global steel output is still very low. Automotive engineering (production up 16% p. 233 5.35 (Governmentof India.66 2005-2006 42. Ministry of Steel. steel.82 17.08 1996-1997 22.34 2007-2008 58.45 2006-2007 55.33 1992-1993 15.59 2008-2009 59.63 3.23 1995-1996 21.4 20.19 2001-2002 30.05 10.7 11.67 9.16 1997-1998 23.86 1998-1999 23.13 2000-2001 29.48 2004-2005 40.2 6.71 12.82 1.2 0 1994-1995 17.02 1.636 6.37 2.72 6.19 7.nic.13 2002-2003 33.146 29.92 2003-2004 36.in) FACTORS HOLDING BACK THE INDIAN STEEL INDUSTRY 20 .YEAR SUPPLY (in m t) GROWTH (in %) 1991-1992 14.92 1999-2000 26.07 1993-1994 15. The growth of the Indian steel industry and its share of global crude steel production could be even higher if they were not being held back by major deficiencies in fundamental areas. India will rely squarely on nuclear energy for its Future power generation requirements. India is the world’s sixth biggest coal importer. In September 2005 the 15th and largest nuclear reactor to date went on-line. Problems procuring raw material inputs: Since domestic raw material sources are insufficient to supply the Indian steel industry. The deficiencies have prompted many firms with Heavier energy demands to opt for producing electricity with their own Industrial generators. Almost half of this is coking coal (the remainder is power station coal).5 million tons of scrap have already been imported in 2006. Inefficient transport system: 21 . a considerable amount of raw materials has to be imported. Energy supply: Power shortages hamper production at many locations. Investment in infrastructure is rising appreciably but remains well below the target levels set by the government due to financing problems. India is likely to be the world’s fourth largest energy consumer by 2010 after the US. In the coming years imports are likely to continue to increase thanks to capacity increases. For this reason hard coal imports have increased in the last five years by a total of 40% to nearly 30 million tons. India’s hard coal deposits are of low quality. compared with just 1 million tons in 2000. Some 3. The rising output of electric steel is also leading to a sharp increase in demand for steel scrap. For example. China and Japan. iron ore deposits are finite and there are problems in mining sufficient amounts of it. The nuclear share of the energy mix is likely to rise to roughly 25% by 2050. Overall. Since 2001 the Indian government has been endeavouring to ensure that power is available Nationwide by 2012. Steel with increased carbon content can be made harder and stronger than iron. but various other alloying elements are used such as manganese.14% by weight (C:110–10Fe). with a carbon content between 0. The story is roughly the same for port facilities and airports. but is also more brittle. chromium. insufficient freight capacity and a transport infrastructure that has long been inadequate are becoming increasingly serious impediments to economic development. In the coming years a total of USD 150 bn is to be invested in transport infrastructure. but containing 1–3% by weight of slag in the form of particles elongated in one direction. depending on grade. preventing dislocations in the iron atom crystal lattice from sliding past one another. and tungsten. Alloys with higher carbon content than this are known as cast iron because of their lower melting point and cast-ability. In the medium to long term this capital expenditure will lay the foundations for seamless freight transport.14% by weight. higher concentrations of carbon or lower temperatures will produce cementite. Varying the amount of alloying elements and form of their presence in the steel (solute elements. Although the country has one of the world’s biggest transport networks – the rail network is twice as extensive as China’s – its poor quality hinders the efficient supply of goods. It is common today to talk about 'the iron and steel 22 . Steel is also to be distinguished from wrought iron containing only a very small amount of other elements. Carbon and other elements act as a hardening agent. and tensile strength of the resulting steel. Carbon is the most cost-effective alloying material for iron. precipitated phase) controls qualities such as the hardness. which offers huge potential for the steel industry. The maximum solubility of carbon in iron (as austenite) is 2. FOREWORD: Steel is an alloy consisting mostly of iron. giving the iron a characteristic grain. It is more rust-resistant than steel and welds more easily.2% and 2. occurring at 1149 °C. ductility.In India. vanadium. 3 COMPANY PROFILE: 23 . 1. but historically they were separate products.industry as if it were a single entity. 24 . 25 . 26 . 27 . MBA(Finance)  Lakshmi Arun. 28 .3. Non-rising stems are used where vertical space is limited or underground.1. Gate valves are sometimes used for regulating flow. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar.4. MS(Industrial Engineering). having been designed to be fully opened or closed. the typical gate valve has no obstruction in the flow path. resulting in very low friction loss. When fully open.Arunachalam. or Sluice Valve. BE(Mechanical Engineering). Gate valves are characterized as having either a rising or a non rising stem. BE(Mechanical Engineering). but many are not suited for that purpose. as it is sometimes known. Rising stems provide a visual indication of valve position. MBA  Arun Arunachalam.1 MANAGEMENT TEAM  Sv.MS(Operations Management) 1.1 GATE VALVE: A Gate Valve. BE(SW Mechanical Engineering).4 PRODUCTS 1. The gate faces can form a wedge shape or they can be parallel. is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. When the valve is closed. When the valve is fully open.1 – GATE VALVE 1. therefore a pressure drop is always induced in the flow regardless of valve position.1. The "butterfly" is a metal disc mounted on a rod. typically used to regulate a fluid flowing through a section of pipe. The plate has a rod through it connected to an actuator on the outside of the valve. The valve is similar in operation to a ball valve.FIGURE 1. Unlike a ball valve.2 BUTTERFLY VALVE: A butterfly valve is a type of flow control device. A flat circular plate is positioned in the centre of the pipe.4.4. Rotating the actuator turns the plate either parallel or perpendicular to the flow. the plate is always present within the flow. the disc is turned so that it completely blocks off the passageway. A butterfly valve is from a family of valves called quarter turn valves. the disc is rotated a quarter turn so that it allows unrestricted 29 . flow will occur. The valve may also be opened incrementally to regulate flow.3 BALL VALVE: A ball valve (like the butterfly valve. The handle position lets you "see" the valve's position. through the middle so that when the port is in line with both ends of the valve. one of a family of valves called quarter turn valves) is a valve that opens by turning a handle attached to a ball inside the valve.2. The ball has a hole. They are therefore an excellent choice for shutoff applications (and are often preferred to globe valves and gate valves for this purpose).4.4. and flow is blocked.passage. FIGURE 1.BUTTERFLY VALVE 1. They do not offer the fine control that may be necessary in throttling applications but are sometimes used for this purpose. Ball valves are durable and usually work to achieve perfect shutoff even after years of disuse. or port. the hole is perpendicular to the ends of the valve. 30 .1. When the valve is closed. 4.4 GLOBE VALVE: A Globe valve is a device (specifically a type of valve) for regulating flow in a pipeline. The ball may be chrome plated to make it more durable.1.4.BALL VALVE 1. This has an opening that forms a seat onto which a movable plug can be screwed in to close (or shut) the valve. FIGURE 1.The body of ball valves may be made of metal. The plug is also called a disc or disk. consisting of a movable disk-type element and a stationary ring seat in a generally spherical body. In globe valves.3. Automated globe valves have a smooth stem rather than threaded and are opened and closed by an actuator 31 . ceramic. Typically. the plug is connected to a stem which is operated by screw action in manual valves. automated valves use sliding stems. or plastic. Globe Valves are named for their spherical body shape with the two halves of the body being separated by an internal baffle. most do not have any valve handle or stem. and/or cheap. Check valves work automatically and most are not controlled by a person or any external control. The bodies (external shells) of most check valves are made of plastic or metal. the stem is turned by a hand wheel. 32 . a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Although they are available in a wide range of sizes and costs. simple.5 CHECK VALVE: A check valve is a mechanical device.4.4. many check valves are very small. accordingly. meaning they have two openings in the body. When a globe valve is manually operated.4. one for fluid to enter and the other for fluid to leave. Check valves are twoport valves. FIGURE 1. Check valves are often part of common household items. There are various types of check valves used in a wide variety of applications.assembly.1 – GLOBE VALVE 1. 6. so that fluid can flow through the plug when the valve is open.1 – PLUG VALVE 33 . FIGURE 1. The plugs in plug valves have one or more hollow passageways going sideways through the plug.4.FIGURE 1. Plug valves are simple and often economical.4.1 – CHECK VALVE 1.5.4.6 PLUG VALVE: Plug valves are valves with cylindrical or conically-tapered "plugs" which can be rotated inside the valve body to control flow through the valve. All twin plug valves have the CCR System which avoids overpressure in the cavity between the two plugs.The design of the lubricated twin-plug valve is very compact.1 – DOUBLE PLUG VALVE 34 .4. Valves. if an emergency –with extreme high overheat. complies with the ASME codes . space and weight is minimized and with face to face dimensions identical to a single plug or ball valve.4.7 DOUBLE PLUG VALVE: These twin plug valves are ideal shut off valves for almost any medium either under severe operation condition or in high explosive areas.7.1. FIGURE 1. should occur. it is called an angle stop valve. A compression mechanism has a threaded stem that tightens a washer or ground joint against the valve seat to stop fluid or gas flow when the handle is turned counter-clockwise. 35 .4. It has inlet and outlet ports aligned at an angle with respect to each other. or they can have compression fittings for connecting to copper pipes. When an angle valve is used as a shut-off valve for residential plumbing fixtures. but when the handle is turned through 90 degrees. on the other hand. The inlet and outlet ports can be threaded for connecting to galvanized steel and iron pipes.1. There are two different valve mechanisms commonly used in angle valves.8 ANGLE VALVE: An angle valve is a fluid regulating device used in plumbing and industry. An angle ball valve. Fluid passes through the hole when the valve is open. the hole aligns perpendicularly to the flow and it stops. as a tight-fitting ball made of metal or plastic with a hole through it. the most common angle being 90 degrees. or simply an angle stop. unified numbering system (UNS) of ASTM International and the Society of Automotive Engineers (SAE).5 Grades of Steel: Steel grades to classify various steels by their composition and physical properties have been developed by a number of standards organizations.EN 10027 For alloys in general (including steel).8.4. 1) 2) 3) 4) 5) SAE steel grades British Standards International Organization for Standardization ISO/TS 4949:2003 European standards .1 – ANGLE VALVE 1.FIGURE 1. 6) Japanese steel grades : Japanese Industrial Standards (JIS) standard 7) Germany steel grades : DIN standard 36 . 0625. WC9. CA6NM 1. LCC.4408. 1. CF3M.8) China steel grades : GB standard STANDARD GRADE EN10213-2 : 1.6220 ASTM A 216 : WCB.Inner Diameter .1GATE VALVE: BODY: Overall length Side Flange .Thickness Bonnet End Flange .7357 EN10213-4 : 1.0619. CF8M.6.4581 EN10213-3 : 1.6 CRITICAL DIMENSIONS OF CASTINGS: 1. C5. 1. CD4MCu.Back to Back .Outer Diameter . 1. CA15 ASTM A 351 : CF3. C12A. CF8. C12. CF8C.4308.OD / Profile Length & Width 37 . WCC ASTM A 217 : WC6. 1. CK3MCuN ASTM A 352 : LCB. ID / Core Profile Length & Width .Outer Diameter 38 . Bottom Width YOKE: Top Flange .Outer Diameter Guide Slot . Width & Thickness Wall Thickness (if applicable).Top Width.. DISC: Thickness .Thickness Guide Rib Thickness Guide Rib to Rib Distance Wall Thickness BONNET: Overall Length Body End Face to Stuff Box Face Stuff Box .Bore Diameter Body End Flange . Thickness & Core Diameter/ Yoke End Flange profile Length.OD / Profile Length & Width ..Top & Bottom Disc . Lug Thickness Yoke Arm Width & Thickness (if applicable) Yoke End Hub Dia.Dome Depth .Width & Face to Face T-Slot .ID / Core Profile Length & Width Eyebolt Lug Gap. Outer Diameter / Profile Square Width .Outer Diameter .2 GLOBE VALVE: BODY: Overall Length Side Flange .Bore Diameter 39 .Pad Thickness Wall Thickness BONNET: Overall Length Body End Face to Stuff Box Face Stuff Box .6.Length ..Back to Back .Width .Inner Diameter .Bore Diameter .Thickness Bottom Leg (Bonnet Seat) .Thickness .Thickness Yoke arm .Inner Diameter .Inner Diameter Bonnet End Flange .Thickness Diffuser ID Seat Ring .Thickness 1.Width . Outer Diameter / Profile Square Width .6.Thickness .Inner Diameter Cover Flange .Back to Back .Thickness Hinge Boss inner Gap Wall Thickness DISC: 40 .Inner Diameter . Lug Gap & Lug Thickness Yoke Arm Width & Thickness Yoke End Hub/ Top flange Diameter.Outer Diameter .Outer Diameter .Thickness .Outer Diameter / Profile Square Width .Body End Flange . Thickness & Inner Diameter DISC: Disc .Inner Diameter Eye Bolt Lug.Length 1.3 CHECK VALVE: BODY: Overall Length Side Flange .Outer Diameter Shank . Inner Diameter Top flange .Disc .Inner Diameter .Diameter HINGE: Hinge .Length .Thickness .4 PLUG VALVE: BODY: Overall Length Side flange .Thickness Cover flange .Inner Step Depth Shank .Inner Diameter 1.Inner Diameter Port width and length 41 .Outer Diameter .Back to Back -Outer Diameter .Outer Diameter .Inner Diameter .Boss Height .Outer Diameter .Boss Diameter COVER: Cover .6.Outer Diameter . Outer Diameter .Inner Diameter Wall thickness DISC: Disc .Inner Diameter .Outer Diameter Top .6.Height Bottom .Thickness .Outer Diameter COVER: Cover .5 BUTTERFLY VALVE: BODY: Overall length Trunion .Width .6 BALL VALVE: BODY: Overall length Side flange .Outer Diameter .6.Outer Diameter .Back to Back 42 .Hub Bore Diameter .Wall thickness PLUG: Port .Height Overall .Face to Face .Hub Length 1.Thickness 1. .Thickness Ball rotating Seat .Inner Diameter 1.Inner Diameter Wall thickness CONNECTOR: Overall Length Side flange .Outer Diameter .Outer Diameter .Outer Diameter .Inner Diameter .Inner Diameter .Inner Diameter .Over Diameter .Thickness Ball rotating .Outer Diameter 43 .Back to Back .Thickness Top flange .7 ANGLE VALVE: BODY: Overall length / height Bottom flange .Inner Diameter Wall thickness BALL: Ball .Inner Diameter .6. Bore Diameter Eye bolt leg .Thickness Yoke arm .Inner Diameter 44 .Thickness Stuff Box .Length .Thickness Top flange .Thickness Bottom Leg (Bonnet Seat) .thickness / gap Wall thickness YOKE: Top Flange .Length .Inner Diameter Yoke seat .Thickness 1.Width .Outer Diameter .8 LOWER BODY: Side flange .Outer Diameter .Outer Diameter .Width .Inner Diameter .Width .Thickness Side flange .Inner Diameter .6..Inner Diameter . Inner Diameter 45 .9 FOUR WAY GLOBE VALVE BODY: Side flange .Outer Diameter .Inner diameter .Back to Back Cover flange .Bore Diameter .Thickness Seat ring .Back to back .Outer diameter .Thickness Wall Thickness 1.Face to Face (Overall Length) .Thickness Bottom flange .Face to face .Bottom flange face Top flange .Thickness .Outer Diameter .Pad thickness Wall thickness Top flange face ..Outer Diameter .Inner Diameter .6.Inner Diameter . Thickness 1.Thickness .12 STEM HOUSING: ..6.Outer Diameter .Bore Diameter .OAL 1.OAL 1.Step OD .13 BODY TUBING SPOOL: Flange .Thickness 1.11 TRUNION: .OAL Height 1.Outer Diameter .Outer Diameter .6.6.6.10 ISO PAD: .Bore Diameter .OAL 46 .Inner Diameter .6.Outer Diameter .14 PUMP CASTING: . 6.Inner Diameter .6.16 GATE CASTING: .Bore Diameter .Bottom Thick .Inner Diameter .15 AGITATOR (OUTER & CENTRAL): – Outer Diameter .Wall Thickness 1.Outer Diameter .Guide Thick .Outer Diameter .OAL 1.Thickness .T slot Width 1.OAL (guide rib face) .6.Outer Diameter ..Seat Diameter 47 .17 Y-BODY (WELD NECK): Side end .Inner Diameter Cover end . Arm width 1.Bore ID .6.OAL Height .18 LOCK RING: .Thickness .Side Face to face .Outer Diameter .Inner Length . For higher productivity in SMEs.Wall Thickness 1.Outer Length .Outer Diameter .6.6. productivity levels of SMEs are alarmingly low due to host of problems (Director of Industries.Inner Diameter ..19 BRACKET: . 48 .Width 1.Thickness CHAPTER 2 LITERATURE REVIEW In India.20 BODY CASTING HEADS: Flange . 2003). 1. 2005). Similarly manufacturing giants like General Electric and Honey Well have been using it as cycle time reduction tool. LG and Samsung etc.. Table 1 cites major works of the researchers related to application of Six Sigma in manufacturing sector during the past decade.Application of SIX SIGMA in Manufacturing Sector 49 . Six Sigma concept has been widely used in manufacturing sector from last 25 years as company like Motorola has been improving its processes since 1986 by using its defect reduction approach (Eckes. Table 2. are also practicing Six Sigma as a quality improvement technique in their respective manufacturing processes from 1999. Other well-known companies like Ford. 2011). After analyzing significant contribution of Six Sigma approach among SMEs. an effort has been made to implement DMAIC methodology in nonferrous (medium scale) foundry.2001). without ignoring its existing Indian constraints.‘Defects reduction’ will be one of the most promising and viable strategy and it will also be capable to cope up the emerging future challenges (Antony et al. Caterpillar. specifically for the foundry unit. Our lady of Lourdes medical centre. since 1996 (Zu et al.. It further demystifies various myths regarding Six Sigma and SMEs. Roughly $10000 per year savings. 6 Antony and Desai (2009) Wilson Tools Shorten the heat treatment time 7 Singh and Khanduja (2010) A copper wire manufacturing plant Quality improvement in rolling operation Parameters Achievements Implementation as a quality tool. (2002) A bulb manufacturing SME 4 Anderson et al. (2006) A gravity die casting unit 5 Lin et al. Optimization of welding process parameters Annual saving of $2 billion Process improvement done Joint strength is increased by 26% and scrap work is reduced by 3% Sigma level increased from 3.5 Improve the process and reduced the shell cracking of bulbs Casting scrap reduced from 23% to 11% CHAPTER-3 BASICS OF FOUNDRY 50 40% reduction in manufacturing cost with annual savings of $72000 p.1 to 4. Reduced the cycle time at repair shops. (2008) Cranberry Drinks Ltd. 17% reduction in packing time. 2% reduction in overall Lead time Defect are decreased by 19% within nine months of DMAIC project .a.S No Author(s) 1 Henderson & Evans (2000) Company / Unit General Electric Company 2 Ingle and Roe (2001) Medium sized welding unit 3 Does et al. Improvement in packing process. DPMO level improved from 3011 to 178 only. Patternmakers learn their 51 . castings. other metals. pouring the metal in a mould.3. brass. Metals are cast into shapes by melting them into a liquid. steel. In this process.2 PROCESSES OF A FOUNDRY:  PATTERN MAKING  METHODING  MOULDING  MELTING  LABORATORY TESTS  FETTLING  QUALITY CONTROL  DESPATCH 3. and removing the mould material or casting after the metal has solidified as it cools. magnesium. but also often incorporates elements of fine woodworking. The most common metals processed are aluminium and cast iron. However. called pattern-making. and zinc. parts of desired shapes and sizes can be formed. are also used to produce castings in foundries. such as bronze. is a skilled trade that is related to the trades of tool and die making and mould making.2. 3.1 FOUNDRY: A Foundry is a factory that produces metal.1 PATTERN MAKING: The making of patterns. skills through apprenticeships and trade schools over many years of experience. Although an engineer may help to design the pattern, it is usually a patternmaker who executes the design. 3.2.1.1 Pattern: In casting, a pattern is a replica of the object to be cast, used to prepare the cavity into which molten material will be poured during the casting process. Patterns used in sand casting may be made of wood, metal, plastics or other materials. Patterns are made to exacting standards of construction, so that they can last for a reasonable length of time, according to the quality grade of the pattern being built, and so that they will repeatedly provide a dimensionally acceptable casting. Typically, materials used for pattern making are wood, metal or plastics. Wax and Plaster of Paris are also used, but only for specialized applications. Mahogany is the most commonly used material for patterns, primarily because it is soft, light, and easy to work. The downside is that it wears out fast, and is prone to moisture attack. Single piece pattern, Multi-piece pattern, Gated pattern, Sweep pattern, Skeleton pattern, Shell pattern and Loose-piece pattern are some of the types of patterns. Metal patterns are more long lasting, and do not succumb to moisture, but they are heavier and difficult to repair once damaged.  In ARUNA ALLOY STEELS PVT LTD, Wood patterns are mainly used.  Country wood, Teak wood, Plywood are being used. 3.2.2 METHODING: 52 The patternmaker or Foundry engineer decides where the Sprues, gating systems, Cores and Risers are placed with respect to the pattern. Where a hole is desired in a casting, a core may be used which defines a volume or location in a casting where metal will not flow into. Sometimes chills may be placed on a pattern surface prior to moulding, which are then formed into the sand mould. Chills are heat sinks which enable localized rapid cooling. The rapid cooling may be desired to refine the grain structure or determine the freezing sequence of the molten metal which is poured into the mould. Because they are at a much cooler temperature, and often a different metal than what is being poured, they do not attach to the casting when the casting cools. The chills can then be reclaimed and reused. The design of the feeding and gating system is usually referred to as METHODING, or methods design. It can be carried out manually, or interactively using general-purpose CAD software.FOOT UP, RISER, CHILL, KALPAD, BRACKET, VENT, METALPAD, etc., are some terms used in METHODING. Foot Up is used to cover extra material and to avoid defects such as Cracks, Pinholes, & Gas holes. Blind & Open are two types of Risers and open riser will be at maximum point; it is part of the gating system that forms the reservoir of molten metal necessary to compensate for losses due to shrinkage as the metal solidifies. Normally, metal will be at room temperature; So, Chills are used to increase the strength of metal. Kalpad is used to maintain the heat of metal. Bracket is used to avoid cracks. Vents are used to remove air from surface. Metal-pad is used for easy flow of metal. Patterns are given 3% allowance. Core boxes are given 2 to 2.5% allowances. 53 3.2.3 MOULDING: Moulding sand, also known as foundry sand, is sand that when moistened or oiled tends to pack well and hold its shape. It is used in the process of sand casting. Greensand is an aggregate of sand, bentonite clay, pulverized coal and water. Its principle use is in making moulds for metal casting. The largest portion of the aggregate is always sand, which can be either silica or olivine. There are many recipes for the proportion of clay, but them all strike different balances between mould ability, surface finish, and ability of the hot molten metal to degas. Green sand (like other casting sands) is usually housed in what casters refer to as flasks, which are nothing other than boxes without a bottom or lid. The box is split into two halves which are stacked together in use. The halves are referred to as the top (cope) and bottom (drag) flask respectively. Green sand is not green in colour, but "green" in the sense that it is used in a wet state (akin to green wood). This dry sand casting process results in a more rigid mould better suited to heavier castings. A sand rammer is a piece of equipment used in foundry sand testing to make test specimen of moulding sand by compacting bulk material by free fixed height drop of fixed weight for 3 times. It is also used to determine compatibility of sands by using special specimen tubes and a linear scale. 3.2.3.1 Specimen Preparation: The cam is actuated by a user by rotating the handle, causing a cam to lift the weight and let it fall freely on the frame attached to the ram head. This 54 and Compression strength of 1kg/cm^2 min.  Facing sand. liquefaction point) of a solid is the temperature at which it changes state from solid to liquid at atmospheric pressure. The melting point of a substance depends (usually slightly) on pressure and is usually specified at standard pressure. At the melting point the solid and liquid phase exists in equilibrium. Backing sand and Core sand must have Permeability of 250 to 500.  Facing sand and Core sand must have Moisture of 1. typically by the application of heat or pressure. and Moisture of 1. and Compression strength of 3kg/cm^2 min. When considered as the temperature of 55 . or other standard foundry tests. rarely. After the specimen has been prepared inside the specimen tube. at which the ordering of ionic or molecular entities in the solid breaks down to a less ordered state and the solid liquefies. the specimen can be used for various standard sand tests such as the permeability test.  Core sand [Chromite sand] must have Permeability of 150 to 500. The object for producing the standard cylindrical specimen is to have the specimen become 2 inches high (plus or minus 1/32 inch) with three rams of the machine.2. resulting in a rise of its temperature to the melting point. the green sand compression test. The internal energy of a substance is increased. An object that has melted completely is molten.60% max. The melting point (or.4 MELTING: Melting is a physical process that results in the phase transition of a substance from a solid to a liquid.60% max. 3. the shear test. Variety of standard specimen for Green Sand and Silicate based (CO 2) sand are prepared using a sand rammer along with accessories.produces a standard compacting action to a pre-measured amount of sand. The opposed magnetic fields 56 . The selection of an appropriate technique is dependent on factors such as the metal being melted.2. which in turn induces eddy currents in the charge.2. These eddy currents heat and eventually melt the metal.the reverse change from liquid to solid.4. the amount of molten metal required for the production run and the area available to house the melting equipment. A second magnetic field is generated by the induced current in the charge.1 Melting Techniques: There are a variety of methods used in foundries for melting the metal for casting.2 Induction Furnace: A water cooled copper coil carrying alternating current produces a magnetic field. 3. The range of melting equipment typically used can be categorised as follows:  Electric Arc Furnaces  Induction Furnaces  Vacuum Induction melting  Hearth Furnaces  Crucible Furnaces  Cupola Furnaces  Vacuum Arc Skull Melting and Casting 3. it is referred to as the freezing point or crystallization point.4. 2.1. FIGURE 3.result in a mechanical force.2. which stirs the molten metal.4.INDUCTION FURNACE 3.5 POURING: 57 .2. The benefits of this stirring include the production of a thermally and chemically homogeneous melt and excellent alloy and charge absorption.  Yield Strength.  Chemical composition of Castings (Bath1&2 and final).  Ultimate Tensile Strength.  Compression strength.2. molten metal is poured into moulds. Fineness number (grain size/AFS Number) of the base sand 2. or it may be assisted with a vacuum or pressurized gas. Permeability and Moisture content of Mould &Core Sand.In a foundry. Traditionally. Pouring can be accomplished with gravity. 3.6 LABORATORY TESTS: The following are some of the tests being carried out in chemical lab:  Micro structure of Scraps. moulds were poured by hand using ladles. A basic set of parameters to test are: 1. Many modern foundries use robots or automatic pouring machines for pouring molten metal.  Elongation%. The following are some of the tests being carried out in mechanical lab:  Hardness.  Reduction%. Moisture content in the mixture (ranges from 2-7% depending on the casting method) 58 . the castings are separated from the sand mould. As castings are removed from the shakeout they are sent to the cleaning room where they are 'finished' to the customer's specifications. The sand is sent to a reclamation system so that it can be reused in the moulding process. welding. Once poured. and risers from the casting. Runners. For some metal types. risers and sprue. sand sampler and sand splitter to do it in a standardized manner. including heads. Permeability (ability of compacted mould to pass air through it) 4. Active clay content (presence of active bentonite/clay which can readily bond) 6. gates. gates.3. At the shakeout. runners and gates can be removed by breaking them away from the casting with a sledge hammer or specially designed knockout machinery. sometimes collectively called sprue that can exceed 50% of the metal required 59 . Processing in the cleaning room includes shot blasting. cut-off. the moulds are allowed to cool before next being sent to the shakeout. De-gating is the removal of the heads. The gating system required to produce castings in a mould yields leftover metal. the sprue.7 FETTLING: The foundry Cleaning Room is collection processes where castings are ‘finished’ to meet the customer’s specifications. 4 and 5 standard bulk material sampling methods can be applicable or sampling can be done with help of sand Muller. heat treating and inspection. Total clay content (dust content) 5.2. Compressive strength For parameters 1. and with some gating system designs. 3. and risers may be removed using cutting torches. band saws or ceramic cut-off blades. 2. runners. Heat treatment techniques include annealing. other metal alloys. To remove this. walnut shells. Some of the methods used for Quality Control are:  Magnetic Particle Inspection. Heat treatment involves the use of heating or chilling.to pour a full mould. and thus melting costs. the yield of a particular gating configuration becomes an important economic consideration when designing various gating schemes. Numerous materials may be used as media. case hardening. This means a granular media will be propelled against the surface of the casting to mechanically knock away the adhering sand. The blasting media is selected to develop the colour and reflectance of the cast surface.2.8 HEAT TREATMENT: Heat treating is a group of industrial and metalworking processes used to alter the physical. Since this metal must be re-melted as salvage. or may be hurled using a shot wheel.9 QUALITY CONTROL: Quality control is the process of assuring the products with no defects and good quality. glass beads. The media may be blown with compressed air. 3. sand. and sometimes chemical. baking powder among others. After de-gating and heat treating. The media strikes the casting surface at high velocity to dislodge the moulding media (for example. to minimize the cost of excess sprue. properties of a material. 3. sand or other moulding media may adhere to the casting. iron. 60 . slag) from the casting surface. aluminium oxides.2. precipitation strengthening. tempering and quenching. the surface is cleaned using a blasting process. including steel. to achieve a desired result such as hardening or softening of a material. normally to extreme temperatures. un-machined castings are packed into wooden crates or boxes depending on the customer’s preference.  Visual inspection. Protective Anti-Rust coatings are given for Carbon steel and Alloy steel.  Penetrant testing. Charging Floor Floor from which the furnace is charged. Charging Machine Machine for charging the furnace. Charging Crane System for charging the melting furnace with a crane. packed and loaded for transportation in this area. Radiographic testing. For very large castings. 61 . Machined castings are given protection covering in machining surface to avoid damages. 3.2.  Dimensional inspection. particularly the open hearth. wooden pallets are used. For export customers.3 TERMS USED IN MELTING AREA OF FOUNDRY: Charge A given weight of metal introduced into the furnace. 3. Charging Door Opening through which the furnace is charged.10 DESPATCH & PACKING Finished products are sorted. tagged.  Ultrasonic testing. and are determined by the liberation of heat when the metal is cooled and by the absorption of heat when the metal is heated. Combustion Chemical change as a result of the combination of the combustible constituents of the fuel with oxygen. resulting in halts or arrests on cooling and heating curves. Corrective Effective Temperature Chart A chart on which information can be plotted resulting in an adjustment temperature reading more indicative of human comfort. Combustion Efficiency The amount of heat usefully available divided by the maximum amount which can be liberated by combustion. De-scale Remove the fire scale from the surface of casting. producing heat. Combustibles Materials capable of combustion. Combustion Chamber Space in furnace where combustion of gaseous products from fuel takes place. Critical Points (Temperatures) Temperatures at which changes in the phase of a metal talk place. Pour off molten metal without disturbing the sludge.Constant Intensity Pyrometer Use of a comparison lamp filament's glow to estimate metal temperature. inflammable. Decant Pour from one vessel to another. 62 . usually expressed in percentage. Disappearing Filament Pyrometer (Optical Pyrometer) A telescope in which a hot body is viewed through an eyepiece and temperature is measured by the matching colour of a calibrated lamp filament with colour of hot metal. of two or more parts to produce a finished assembly. Electrical Precipitator In air pollution control. as steel. 63 . The components of the assembly may be a combination of cast and wrought materials. Firebrick Brick made of refractory clay or other material which resists high temperatures. Fabrication The joining usually by welding. Fettle A British term meaning the process of removing all runners and risers and cleaning off adhering sand from the casting. particles 0.Designations Type of metal named. malleable. Also refers to the removal of slag from the inside of the cupola and in Britain to repair the bed of an open hearth. similar to an electric arc welding operation. etc. Electric Arc Furnace A crucible furnace that uses an electric arc. nonferrous. Foundry (Foundries. to melt metal.1 micron and smaller can be attached and collected at discharge electrode. the use of electrodes in stack emissions emitting high voltage. Filter The filtering out of unwanted gases in the casting at pouring off portion of making the casting. plural) A process or art of casting metals. Feed Material The volume of molten metal from which a casting feeds as it shrinks (contracts) during solidification. The buildings and works for casting metals. a form used for convenient handling of cast iron. Hand Ladle or Shank A small ladle carried by one man. gates. with known chemical composition that are returned to the furnace for remelting. and which is supplied from a large melting unit.Foundry Ladle A vessel for holding molten metal and conveying it from furnace to the moulds. Inclusion(s) Particles of slag. 64 . Heel Metal left in a ladle after pouring or in a furnace after or between tapping. Foundry Returns Metal in the form of sprues. and other commercial metals. aluminium. which utilizes the heat of electrical induction. Induction Heating Process of heating by electrical resistance and hysteresis losses induced by subjecting a metal to the varying magnetic field surrounding a coil carrying an alternating current. Holding Furnace Usually a small furnace for maintaining molten metal at the proper pouring temperature. a heat may be all of part of a master heat. Holding Ladle Heavily lined and insulated ladle in which molten metal is placed until it can be used. refractory materials. Ingot Casting to be later forged or hot worked. risers and scrapped castings. sand or de-oxidation products trapped in the casting during solidification. Also. Induction Furnace AC melting furnace. Heat A single furnace charge of metal to be used for pouring directly into mould cavities. runners. holding. Melting Rate Amount of metal melted in a given period of time. Teapot A ladle in which. clay.16°C. Melting Range Pure metals melt at one definite temperature. Lining Inside refractory layer of firebrick. 65 . Melting Pot Vessel in which metal is melted. Bottom-Pour Ladle from which metal flows through a nozzle in the bottom. Ladle Metal receptacle frequently lined with refractory used for transporting and pouring molten metal. bottom-pour. and lip-pour. usually one hour. and the variation from the lowest to the highest is called the melting range.Iron-Carbon (Graphite) Diagram A diagram representing stable equilibrium conditions between iron and graphite (pure carbon) phase over the entire range of iron and steel. by means of an external spout. but constituents of alloys melt at different temperatures. crane. Ladle. metal is removed from the bottom rather than the top of the ladle. Melting Zone Portion of furnace in which the metal melts. or other material in a furnace or ladle. teapot. shank. Kelvin Temperature Scale One in which the unit of measurement equals that of the centigrade degree and according to which absolute zero is 0 degrees. sand.000 volts. equivalent to -273. Different types of ladles include hand bull. Kilovolt (kV) Unit of electrical potential equal to 1. Ladle. Metallurgy Science dealing with the constitution, structure, and properties of metals and alloys, and the processes by which they are obtained from ore and adapted to the use of man. Mica Schist A type of refractory rock used for lining cupolas and other melting furnaces. Nozzle Pouring spout of the bottom -pour ladle. Nozzle Brick A thick-walled tubular refractory shape set in bottom of a ladle through which steel is teemed. Open Flame Furnace As opposed to the crucible furnace; in the open-flame furnace the metal charge is confined in the refractory lining, with the flame and products of combustion coming in direct contact with the metal. Open Riser Riser whose top is open to the atmosphere through the top of the mould. Optical Pyrometer A temperature measuring device through which the observer sights the heated object and compares its incandescence with that of an electrically heated filament whose brightness can be regulated; or the intensity of the light admitted from the object may be varied through filters and compared with a constant light source. Orifice An opening of controlled size used to measure or control the flow of gases. Oven, Drying A furnace or oven for drying moulds or cores. P1 In production, acceptable quality level. P2 In production, lot tolerance. 66 Patching Repair of a furnace lining or repair of a mould core. Peel Free removal of burnt moulding sand from casting. Pencil Core A core projecting to the centre of a blind riser allowing atmospheric pressure to force out feed metal. Pour Discharge of molten metal from the ladle into the mould. Pouring Filling the mould with molten metal. Transferring the molten metal from the furnace to the ladle, ladle to ladle, or ladle into the moulds. Pouring Basin Reservoir on top of the mould to receive the molten metal. Pouring Basin, Cup Located on top of sprue or down gate. Pouring Cup The flared section of the top of the downsprue. It can be shaped by hand in the cope, or be a shaped part of the pattern used to form the downsprue; or may be baked core cup placed on the top of the cope over the downsprue. Pouring Device Mechanically operated device with a ladle set for controlling the pouring operation. Pouring Ladle Ladle used to pour metal into the mould. Pouring Off The task of ladling, or mechanically pouring, of the molten metal into the moulds, forming the casting. Production Foundry Highly mechanized foundry for manufacturing large quantities of repetitive castings. 67 Production Welding Any welding carried out during manufacturing before final delivery to the purchaser. This includes joint welding of casting and finishing welding. Purging Elimination of air and other undesirable gases from furnaces or heating boxes. Pyrometallurgy Chemical metallurgical process dependent upon heat. Pyrometer An instrument for determining elevated temperatures. Pyrometric Cone A slender trihedral pyramid made of a mixture of minerals similar in composition to that of clay or other refractory being tested. Each cone is assigned a number indicating its fusion temperature. Pyrometric Cone Equivalent (PCE) An index of refractoriness obtained by heating on a time-temperature schedule a cone of the sample material and a series of standardized pyrometric cones of increasing refractoriness. Pyrometry A method of measuring temperature with any type of temperature indicating instruments. Rare Earth (RE) Any of a group of 15 similar metals with atomic numbers 57 to 71. Also rare earth element, rare earth metal, lanthanide series, uncommon metals, Misch metal. Rare Gases These include helium, argon, neon, krypton, xenon and radon. Re-bonding Term usually employed in reference to adding new bonding material to used moulding sand so that it can be used again to produce moulds. Receiving Ladle A ladle placed in front of the cupola into which all metal is tapped. It acts as a mixer and reservoir and to smooth out metal flow to the pouring area. 68 Reverberatory Furnace Melting unit with a roof arranged to deflect the flame and heat toward the hearth on which the metal to be melted rests. 69 . The quality of resisting heat. sprues. Material usually made of ceramics. defective castings and machine chips. Laminar flow is seldom experienced in runner and gating systems. Reynolds Numbers Used in hydraulics and in casting gating theory. Revert Recycled sprues. expressed as a percentage. Repair Welding Any welding carried out after delivery to the end user. Re > 2000 represents turbulent flow. i.. loose pieces. Returns Metal in the form of gates. Reject Rate Ratio of the number of parts scrapped to the total number of parts manufactured. Riddle Hand or power-operated device for removing large particles of sand or foreign material from foundry sand. needed on the pattern to produce a sound casting. molten metal. A dimensionless value (dynamic viscosity / density) describing the fairly sudden shift of flow from laminar to turbulent. gates. risers or defective castings which are put back into the melting cycle. etc. used for furnace linings etc. risers.. Rigging Gates. after the casting has been in service. risers. and slag attack. which is resistant to high temperatures. Relief Sprue The term usually refers to a second sprue at opposite end of the runner to relieve pressure created during pouring operation.e. usually non-metallic.Refractory Heat-resistant material. polish. Sand Casting Metal castings produced in sand moulds. 70 . castings that have to be re-melted). or decorate glass or other hard substances.Riser A reservoir of molten metal that the casting can draw from to offset the shrinkage that is taking place as the metal solidifies. usually with suitable additions. Sand Blast Sand driven by a blast of compressed air (or steam). It is used to clean castings. Sodium Silicate (CO2 Process) Moulding sand is mixed with sodium silicate and the mould is gassed with carbon dioxide gas to produce a hard mould or core. and also to clean building fronts. Scarfing Cutting off surface projections such as gates and risers from casting by means of gas torch. and fired at high temperature. etc. includes scrapped machinery fabricated items such as rail or structural steel and rejected castings (metal to be re-melted. Runner Box System into which molten metal is introduced. Shank The handle attached to a small ladle. bonded with hydrated lime. Silica Brick Refractory material of ganister. to cut. Scrap Metal Metal to be re-melted. Runner Trapezoidal shaped piece that runs horizontally to the mould cavity and connects the Sprue base to the gate(s). Scrap Any scrap metal melted. to produce castings. Tap To withdraw a molten charge from the melting unit. Sprue A vertical passageway that takes the molten metal from the pouring basin to the runner. Test Bar Standard specimen bar designed to permit determination of mechanical properties of the metal from which it was poured. Fahrenheit. Pouring The temperature of the metal as it is poured into the mould. Teapot Ladle Ladle with external spout wherein the molten metal is poured from the bottom rather than from the top. as Centigrade. Measured in Pounds per Square Inch (PSI) . The temperature maintained when metal is held in a furnace. Temperature Degree of warmth or coldness in relation to an arbitrary zero measured on one or more of accepted scales. usually prior to pouring. Holding Temperature above the critical phase transformation range at which castings are held as a part of the heat treatment cycle. Temperature.Solidification Process of metal (or alloy) changing from the liquid to the solid state. Spout A trough through which the metal flows from the furnace to the ladle. or thousands of pounds per square inch (KSI). Temperature. etc. UTS) A measure of the amount of mechanical stress a material can withstand before it fractures. Tap Hole Opening in a furnace through which molten metal is tapped into the ladle. Spruing Removing gates and risers from castings after the metal has solidified. 71 . Tensile Strength (Ultimate Tensile Strength. Cope The top half of a horizontally parted mould. Drag The bottom half of a horizontally parted mould Gate The connection to the casting cavity through which the molten metal flows. Transfer Ladle A ladle that may be supported on a monorail or carried in a shank and used to transfer metal from the melting furnace to the holding furnace or from furnace to pouring ladles. Vent A pathway provided in the mould to allow gas to escape. Transformation (Temperature) Range The critical temperature at which a change in phase occurs. Thermocouples are used to operate temperature indicators or heat controls. usually baked or chemically bonded.Test Lug A lug cast as a part of the casting and later removed for testing purposes. Thermocouple A device for measuring temperatures by the use of two dissimilar metals in contact. inserted in a mould to form the inside of a casting or parts which could not otherwise be shaped by the pattern. Core A separately made sand shape. the junction of these metals gives rise to a measurable electrical potential which varies with the temperature of the junction. Parting Line The line along which a pattern or core box is divided or the dividing line 72 . between sections of a mould. It is a silvery white. 73 . ductile metal. It is a steely-gray. soft. resists tarnishing. and used to increase the amount of such elements in ferrous metals and alloys.4 METALS USED IN A FOUNDRY: Aluminium Aluminium is a chemical element in the boron group with symbol Al and atomic number 13. Chromium Chromium is a chemical element which has the symbol Cr and atomic number 24. lustrous. 3. hard and brittle metal which takes a high polish. in the Earth's crust. Pure copper is soft and malleable. Aluminium is the third most abundant element. In some cases the ferroalloys may serve as deoxidizers. and has a high melting point. Melting point: 660. and the most abundant metal. Melting point: 1.085 °C Eutectic The alloy which has the lowest melting point possible for a given composition Ferroalloys Alloys consisting of certain elements combined with iron. it is non-metallic and tetravalent— making four electrons available to form covalent chemical bonds. Melting point: 1. a freshly exposed surface has a reddish-orange colour.907 °c Copper Copper is a chemical element with the symbol Cu and atomic number 29. It is the first element in Group 6.3 °C Carbon Carbon is the chemical element with symbol C and atomic number 6. It is a ductile metal with very high thermal and electrical conductivity. As a member of group 14 on the periodic table. Melting point: 1. 74 . argon or helium. It has the atomic number 25. Melting point: 1..g. Inert Gas A gas that will not support combustion or sustain any chemical reaction.High-Alloy Steel Ferrous alloy with more than 12 weight percent of non-carbon additions. neodymium.538 °C Manganese Briquettes Crushed ferromanganese bonded with a special refractory in briquette form. e. Iron Iron is a chemical element with the symbol Fe and atomic number 26.246 °C Mild Steel Plain carbon steel of about 0. and similar elements. designated by the symbol Mn. Mineral Natural inorganic substance which is either definite in chemical composition or physical characteristics or any chemical element or compound occurring naturally as a product of inorganic processes. It is found as a free element in nature. Misch-metal Alloy of rare-earth metals containing about 50% cerium and 50% lanthanum. and in many minerals. and containing 2-lb metallic manganese and ½-lb metallic silicon. forming much of Earth's outer and inner core.25% carbon or less. It is a metal in the first transition series. Manganese Manganese is a chemical element. It is by mass the most common element on Earth. melting point 1455°C (2651°F). formerly columbium. At room temperature.452°C. it is a gas of diatomic molecules and is colourless and 75 . Si and other elements. It is used as hardening element for steel. approximately 67% Ni. which is often found in the pyrochlore mineral. Nickel’s chemical symbol is Ni. Niobium Niobium. Mother Metal The molten alloy just before final solidification and freezing out of the solid. is the chemical element of atomic number seven. 28% Cu. ductile transition metal. grey. is a chemical element with the symbol Nb and atomic number 41.69 and the specific gravity is 8. It is a soft. and nickel’s melting point 1. the balance Fe. and 15% Cr. the main commercial source for niobium.620°C (4.748°F). Melting point: 2.Monel A high nickel alloy. Monel metal is resistant to corrosion and is widely used to resist the action of acids. The melting point is 2. and the atomic number is 42. Molybdenum A metal used widely in alloying of other metals. Nichrome Oxidation-resistant alloy 65% Ni. and columbite. and for die-casting dies.469 °C Nitrogen Nitrogen. Nickel is also a base metal for many casting alloys resistant to corrosion and high temperature oxidation. Its formula weight is 58. Mn. symbol N.90. Nickel An element used for alloying iron and steel as well as nonferrous metals. 20% Fe. its chemical symbol is P.odourless. specific gravity 1. Phosphorus One of the elements.4ƒF). by Scottish physician Daniel Rutherford. melting point 1423ƒC (2593. Its formula weight is 123. Ore A mineral from which a metallic element may be extracted profitably Pearlite A micro-constituent of iron and steel consisting of alternative layers of ferrite and iron carbide or cementite Plaster of Paris A semi-hydrated form of calcium sulphate made by sintering gypsum to 120°C-130°C (248°F-266°F). and melting point 44. estimated at about seventh in total abundance in our galaxy and the Solar System. Nitrogen is a common element in the universe. The element nitrogen was discovered as a separable component of air. metallurgically a metal.92. Silicon An abundant element. the element is primarily found as the gas molecule. 76 . used extensively in ferrous and nonferrous alloys.1°C. chemically classed as a non-metal. On Earth. in 1772.82. it forms about 80% of Earth's atmosphere. specific gravity 7. Super alloy An alloy developed for very high temperature use where relatively high stresses are encountered and where oxidation resistance is needed.85°C. Tin A chemical element having symbol sn.2°F) occurring as an undesirable tramp (trace) element in most ferrous alloys.70. with a melting point of 444°C (831. Titanium A white metallic element. Sulphur A non-metallic chemical element. 77 . useful in aircraft parts. melting point 1660°C (3020°F). having a high strength-to-weight ratio.74% carbon. formula weight 118.31. It must be malleable at some temperature while in the as-cast state. and melting point 231. exhibiting high resistance to corrosion Steel An alloy of iron and carbon.Selenium A metalloid melting 220°C (428°F) added to stainless steel to improve machinability Stainless Steel A wide range of steels containing chromium or chromium and nickel. containing no more than 1. Ternary Alloy An alloy that contains three principal elements. not previously used. CHAPTER 4 CASE STUDY Product -Castings Materials . x-ray tube target. a powerful carbide stabilizer and deoxidizer. mp 1.860°C (3.140. and as alloy element in high-speed steels. mp 1800°C (3272°F). used as an alloy in iron and steel.38. specific gravity 7. Zirconium Silvery-white. and melting point 419.380°F). metallic element. Virgin Metal (Primary Metal) Metal extracted directly from the ore. Vanadium A white. formula weigh 65.ASTM A216 WCB ASTM A351 CK3MCuN 78 . hard. mp 3380°C (6116°F) used for electric lamp filament. metallic element.4°C.Tungsten Steel-gray. a powerful deoxidizer when added to molten steel. metallic element. Zinc A chemical element having symbol Zn. 1 PROBLEM SOLVING TECHNIQUES: Techniques used for solving this problem are “Statistical Quality Control (SQC)” and “Six Sigma”. SQC is used to analyze the quality problems and solve them. They are called basic because they are suitable for people with little formal training in statistics and because they can be used to solve the vast majority of quality-related issues. 4. Descriptive Statistics involves describing quality characteristics and relationships. 4. All the tools of SQC are helpful in evaluating the quality of services. Statistical quality control refers to the use of statistical methods in the monitoring and maintaining of the quality of products and services. SQC uses different tools to analyze quality problem. SPC involves inspect random sample of output from process for characteristic.1 STATISTICAL QUALITY CONTROL Statistical Quality Control (SQC) is the term used to describe the set of statistical tools used by quality professionals. Acceptance Sampling involves batch sampling by inspection.Problem:  Crack in castings.1. The seven tools are:  Cause-and-effect diagram (also known as the "fishbone" or Ishikawa diagram)  Check sheet  Control chart  Histogram  Pareto chart  Scatter diagram 79 . The Seven Basic Tools of Quality is a designation given to a fixed set of graphical techniques identified as being most helpful in troubleshooting issues related to quality. The Project Management Institute references the Seven Basic Tools in A Guide to the Project Management Body of Knowledge as an example of a set of general tools useful for planning or controlling project quality. At that time. Six Sigma DMAIC is a process that Defines. flow chart or run chart) The designation arose in postwar Japan. and various methods developed in the field of operations research. each term derived from the major steps in the process. and analyzing results to a fine degree as a way to reduce defects in products and services. It was possibly introduced by Kaoru Ishikawa who in turn was influenced by a series of lectures W. The Seven Basic Tools stand in contrast to more advanced statistical methods such as survey sampling. Edwards Deming had given to Japanese engineers and scientists in 1950. In order for a company to achieve Six Sigma. 4.4 defects per million opportunities. and controls existing processes that fall below the Six Sigma specification. you can figure out how to systematically eliminate them and get as close to perfection as possible. where an opportunity is defined as a chance for non conformance. Stratification (alternately. measures. it cannot produce more than 3. The Greek letter sigma is sometimes used to denote variation from a standard. analyzes. acceptance sampling. multivariate analysis. design of experiments. There are two Six Sigma processes: Six Sigma DMAIC and Six Sigma DMADV.2 SIX SIGMA Six Sigma is a management philosophy developed by Motorola that emphasizes setting extremely high objectives.1. collecting data. companies that had set about training their workforces in statistical quality control found that the complexity of the subject intimidated the vast majority of their workers and scaled back training to focus primarily on simpler methods which suffice for most quality-related issues. Six Sigma 80 . inspired by the seven famous weapons of Benkei. improves. statistical hypothesis testing. The philosophy behind Six Sigma is that if you measure how many defects are in a process. designs.2. 4. It is acknowledged that Six Sigma can be costly to implement and can take several years before a company begins to see bottom-line results.1 DMAIC methodology:  DMAIC methodology is used to root out and eliminate the causes of defects. General Electric. which are then overseen by a Six Sigma Master Black Belts.DMADV Defines. and Allied Signal are a few of the companies that practice Six Sigma. Phase V: Control The purpose of this phase is to lock in the benefits achieved by doing the 81 . measures.cycle-time improvement. and more reliable products and services. analyzes. and verifies new processes or products that are trying to achieve Six Sigma quality. Phase II: Measure The purpose of this phase is to gather data on the problem. Scientific-Atlanta. All Six Sigma processes are executed by Six Sigma Green Belts or Six Sigma Black Belts. Phase III: Analyze The purpose of this phase is to examine the data and process maps to characterize the nature and extent of the defect. less waste of materials. increased customer satisfaction. Phase IV: Improve The purpose of this phase is to eliminate defects in both quality and process velocity.1. Six Sigma proponents claim that its benefits include up to 50% process cost reduction. terms created by Motorola. a better understanding of customer requirements. Phase I: Define The purpose of this phase is to clarify the goals and value of a project. Texas Instruments. 1 – CK3MCuN castings with Scraps Heat No: Status RT NSD% K7748 K7837 K7668 K7715 Rejection Rejection Rejection OK 50% 50% 75% 100% Weld% 1.87% 82 Chemical Compositio n OK OK OK OK Mechanical properties OK OK OK OK .1.1 – FISHBONE DIAGRAM FOR DEFECTS IN CASTING Table 4. Phase II&III: Measure and Analyse FIGURE 4.1.1.2.1.2.previous phases. Phase I: Define The problem can be defined as Cracks and other defects found in castings. 3 –WCB castings with Scraps Heat No: Status RT NSD% Weld% Mechanical properties 3.2.1.4 –WCB castings with Scraps + Returns 83 OK .78% OK OK K6741 OK 82.K7502 K7378 K7432 OK Rejection OK 100% 0.1.2.1.89% OK OK OK OK OK OK Table 4.1.2.50% 1.82% 100% 0.93% Chemical compositio n OK OK OK OK OK OK Mechanical properties OK OK OK OK OK OK Table 4.2-CK3MCuN castings with Scraps + Returns Heat No: Status RT NSD% K7868 K7906 K7629 K7643 K7513 K7521 OK OK Rejection Rejection Rejection R OK 100% 100% 50% 50% 50% 100% Weld% 0.1.90% 5.90% K6740 OK 81.22% Chemical compositio n OK K 6739 OK 78.11% OK OK Table 4.1. 2.2– RT % of WCB castings with Scraps & Scraps + Returns Heat No: Statu s RT NSD% Weld % Chemical compositi on K674 8 K675 1 K675 2 K675 6 K676 1 K676 2 K676 4 K676 5 K676 6 OK 63% OK OK 81.54% OK OK 0.66% OK OK 0.70 % 48.1.30 % 89.50 % 75.60 % 83.66% Mechanic al Propertie s OK OK OK 9.18% OK OK 3.50 % 63.Figure 4.52% OK OK 3.1.80 % 15.60 % 94.17 % 1.1.3 – Weld% of WCB castings with Scraps &Scraps + Returns 84 .67% OK OK 3.2.81% OK OK OK OK OK OK OK OK OK NSD Figure 4.1.78% OK OK 1.20 % 73. 2.Figure 4.4 – RT NSD% of CK3MCuN castings with Scraps& Scraps + Returns Figure 4.1.2.1.5 – Weld% of CK3MCuN castings with Scraps& Scraps + Returns 85 .1.1. 01 K7629 364.27 Table 4.22 406.2.35 Metal cost / Kg Scrap + Returns Heat No Rate K7513 408.62 K7643 392.5 Cost analysis of CK3MCuN Castings with Scraps & Scraps + Returns Scraps Heat No K7378 K7432 K7502 K7668 K7715 K7748 K7837 Rate 409.45 K7906 391.1.1.09 413.59 413.71 413.Table 4.4 406.53 K7868 390.6 Cost analysis of WCB Castings with Scraps & Scraps + Returns Scraps Metal cost / Kg Scraps + Returns 86 .2.99 K7521 401.1.75 416.1. Cost is being reduced and Quality gets improved.09 36.49 38. No K6739 K6740 K6741 Rate Heat .75 42. This is a preventive act. Most commonly employed.1.2 VISUAL INSPECTION It is the simplest and fastest inspectional methods.91 37.1 INSPECTION OF CASTING: 5. CHAPTER 5 METHODS OF MEASURING THE DEFECTS 5.No 46. Usually good to check surface defects.53 41.1.3 DIMENSIONAL INSPECTION Before casting is to be machined dimensional inspection is done.12 PHASE IV AND V: IMPROVE AND CONTROL Scraps and Foundry returns are regularly made as Melting charges.1 PROCESS INSPECTION Inspection which is done while parts are being processed. but fails to identify internal defects.1.3 K6762 K6751 K6764 K6765 K6766 K6748 K6752 Rate 40. This is helpful to detect defects at the start and allow the corrections.66 K6756 46 K6761 44. 5. 87 . instead of using only scraps.87 40.Heat.6 42. 5.08 42. gases. 5. creep tests etc. Various measuring instruments are employed for a first set of castings. cast iron etc Principle: When a metal placed in magnetic field.1 PRESSURE TESTING: Casting that is used for containing or conveying liquids. compression tests.2.3 NON DESTRUCTIVE TESTING [NDT]: Here parts to be tested are inspected for internal defects and surface defects without destroying the component.3. 5. by destroying it.measuring instruments. cheap and very sensitive.2 DESTRUCTIVE TESTING: This test is done causing harm to the casting i.2. It is quick. This can detected when magnetic particles are attracted towards defective region.2. Can only be applied to ferrous metals like steel. Leaks may be detected by submerging the complete casting under water for gas pressures or by visual inspection by liquid pressures. magnetic flux is intersected by the defect Magnetic poles are induced on either side of discontinuity. Various tests include fatigue tests.2.2 TESTING METHODS 5.e. 5.Castings are placed on surface plate or surface table with angle . Various methods available are: 5. 88 . so as to standardize subsequent castings. It is tested for any leaks through their walls. such type are subjected to pressure testing.1Magnetic Particle Inspection – MPI: Most satisfactory method Used to find surface and sub surface defects. This process is called activation. Two most commonly used gamma ray sources in industrial radiography are iridium 192 and cobalt 60.carried out in good light.2. A radiographic film is placed next to the part to be tested and gamma rays are directed against the part.3. If no defects then regular pattern.2. The gamma rays will pass through the part to be tested proportional to the density and thickness of the part. Most of the radioactive material used in industrial radiography is artificially produced.Magnetic particles piles up in defective region.1. Gamma rays are similar to X. 89 . A radioisotope has unstable nuclei that do not have enough binding energy to hold the nucleus together.Magnetic particle inspection 5. Inspection of defect: Generally. This is done by subjecting stable material to a source of neutrons in a special nuclear reactor. Gamma rays are emitted from the nucleus itself during the process of radioactivity. if presence of defects then flux lines distorted. Magnetic particles spread out at the point of defects indicating presence of defect. and Gamma Ray are the two type of sources used for Radiographic testing. Figure 5.1.2 Radiographic Testing: X-Ray. Gamma rays are produced by a radioisotope. The spontaneous breakdown of an atomic nucleus resulting in the release of energy and matter is known as radioactive decay.3.Rays except that they have much shorter wavelength and differ in their origin. the penetration of gamma rays will move through them which shows as darker areas on the film. magnesium etc.The absorption of gamma rays is directly proportional to the density of and thickness of the part.1 –Radiographic testing 90 .3.2. piping. If the part has no defects. shrinkage.2. Figure 5. porosity. pin holes etc. the gamma rays will pass uniformly through the part. blow holes. slag inclusions. like steel. aluminium. Gamma rays can be used for inspection of casting in all type of metals. However if there are any defects such as porosity which leads to higher density. Gamma rays technique is effective in locating cracks. We have world's latest and sophisticated gamma ray projectors and proud to say that we are the only private agency in India having a maximum number of Cobalt -60 (TECH OPS) exposure devices.2 –Radiographic testing Cobalt-60 Radiography Testing: Figure 5. Iridium-192 Radiography Testing: 91 .2.3.Figure 5.2.3.2.3 – Cobalt 60Radiographic testing Cobalt-60 is a preferred source for the radiography of steel thickness of about 75mm to 200 mm.2. 3.5 92 .2.3.8 3.4 –Iridium 192 Radiographic testing Iridium 192 Radiography: Iridium -192 is used for radiography of steel thickness of about 6mm to 75 mm. Half-life of two widely used industrial isotopes are. and 5. 74 days for Iridium-192.3 2.8 Cobalt-60 21.6 12.2. Figure 5.5 12.9 6.2. We have Exposure devices (SPEC2T & TECH OPS) that are all imported and the latest.3 years for Cobalt-60.2.5 –Penetrating Power of Radiation Table 5.2.9 60.2.Figure 5.3.1 –Penetrating Power of Radiation Source Concrete Steel Lead Tungsten Uranium Iridium192 44.5 7.7 4. Figure 5.The reflected wave signal is transformed into an electrical signal by the transducer and is 93 .2. The crystal expands in full half of the cycle and contracts when the electric field is increased.3Ultrasonic Testing: Ultrasonic Testing (UT) uses high frequency sound energy to conduct examinations and make measurements.2.2.2.5 mm.2. part of the energy will be reflected back from the flaw surface . thus producing mechanical vibrations.3.3. Ultrasonic testing is based on piezoelectric effect which converts electrical energy to mechanical energy thus generating ultrasonic waves . When there is a discontinuity (such as a crack) in the wave path.5 mm x 1. but generally an isotope material is a pellet that measures 1. Table 5.2.6 – Radioactive Isotope Material Physical size of isotope materials varies between manufacturers.Selection of Radiation Sources Radiation source Iridium -192 Cobalt 60 Linear Accelerators 7.Ultrasonic waves are generated when a high frequency alternating current of about a million times per second is impressed across the forces of piezoelectric materials like quartz crystal.3.5Mev (X Part Wall Thickness 18 to 60 mm 40 to 200 mm Above 70 mm 5. 3.3.1 -ULTRASONIC TESTING 5. information about the reflector location.4 PENETRANT TESTING 94 . the reflected signal strength is displayed versus the time from signal generation to when an echo was received. FIGURE 5. orientation and other features can be found.2. Signal travel time can be directly related to the distance that the signal travelled .3.2.From the signal. size.In the applet below.displayed on a screen . As these materials are non-magnetic.DYE PENETRANT TESTING 95 .3. Solvent removable is done on Customer’s inspection requirements.4.2.LTD.1. Mostly. Super Duplex and Nickel Alloy castings. Water washable and solvent removable methods are being practiced in ARUNA ALLOY STEELS PVT. FIGURE 5.Penetrant testing is 100% performed on Stainless Steel. it is done to identify Cracks and surface defects. Duplex. 96 . partially marking the paths of metal flow through the mould.  Possible Causes Oxide films which lodge at the surface.  For metallic moulds. 97 .  Care in core setting and mould assembly. Defective Surface  Flow marks: On the surfaces of otherwise sound castings.  Increase static pressure by enlarging runner height. delay knockout. Discontinuities  Care in shakeout and in handling the casting while it is still hot.CHAPTER 6 AVOIDING THE DEFECTS IN CASTING Metallic Projections  Care in pattern making. moulding and core making.  Control of their dimensions. use ejector pins.  Control moisture levels in green sand moulding. Cavities  Make adequate provision for evacuation of air from the mould cavity.  Increase permeability of mould and cores.  Assure adequate baking of dry sand moulds. assure mould alignment.  Avoid improper gating systems.  Sufficient cooling of the casting in the mould. the defect appears as lines which trace the flow of the streams of liquid metal. or nearly perpendicular.  Check the gating system.  Use small pieces of alloying material and master alloys in making up the charge. especially when squeeze pressures are being increased.Remedies:  Increase mould temperature.  In die casting: vapour blast or sand blast mould surfaces which are perpendicular. Incorrect Dimensions or Shape  Assure adequate rigidity of patterns and pattern plates.  Do not make addition to near to the time of pouring. eliminate foreign metals.  Be sure that the bath is hot enough when making the additions.  Tilt the mould during pouring. 98 .  Modify gate size and location (for permanent moulding by gravity or low pressure).  Lower the pouring temperature. Incomplete Casting  Have sufficient metal in the ladle to fill the mould. to the mould parting line.  Instruct pouring crew and supervise pouring practice. Inclusions or Structural Anomalies  Assure that charge materials are clean. protect cast iron crucibles with a suitable wash coating. 99 . For nonferrous alloys.  Enhance capabilities and invest in new technology to improve productivity and supply finished products for severe and critical applications. MISSION  Continually delight the customer with quality and on-time delivery for forging long term sustainable win-win partnerships. Environmentally friendly and dependable World Class Steel Foundry manufacturing machined valve castings for severe and critical application in complex materials.ANNEXURE VISION Safe. 2011 201 0 - Largest C12A Casting 24” 1500 GTV weighing 5.  Continuously invest and develop people with core skills to improve competency and organizational involvement.  Continually improvise effectiveness of management to strengthen the system and focus people on data driven decision analysis and problem solving.500 Kg manufactured successfully - 36 Strainer bodies with short delivery supplied for ARAMCO Karan Gas Project - Steel Valve machining facility with Hydro Test upto 24” 2500 & 36” 300 started - 100 Curie Radiography Co 60 Bunker constructed - Customized ORACLE ERP System developed in-house and installed 100 . 1.6982 CF10 STAINLESS STEEL CK3MCuN 1.5419.4470 Inconel CW6MC.6220 ASTM A352 LC2.4309 DIN 10213-4 ASTM A890 ASTM A995 / A890 101 GA 1.1131. CF3M. WC6. C12A CA15 ASTM A743 ASTM A487 CA6NM.4408.0619. WCC ASTM A352 LCB. LCC DIN 10213-2 1.4552 GL 1A (CD4MCu) CH 1B PLU 4A (CD3MN) CO 5A (CE5MN) BU 1. 1. Cu5MCuC ASTM A494 Val 1. CG3M DUPLEX 200 8 WC1.0625 DIN 10213-3 1. CF8C. CG8M ASTM A351 DIN 10213-4 200 7 CA40 CF3. LC9 C5. 4D. 1. LC3. 1. 1. CF8M.ASTM Standard Category CARBON STEEL Standard Grade ASTM A216 WCB.7357. 4C.4409 6A (CD3MWCuN) NICKEL ALLOY 200 6 CF8.7365 DIN 10213-3 1. 120-95 DIN 10213-2 1.7379. 1. 4Q ASTM A148 90-60. WC9 ASTM A217 ALLOY STEEL 200 9 Monel M35-1 . C12. 1.4308. Adaptor. Trunion Y-GLOBE Body PROCESS FLOWCHART 102 . Connector.ANGLE Body BALL Body. Ball. 103 . 104 . Packing and Despatch 105 . ORGANIZATIONAL STRUCTURE MD JMD AMD Purchase & Admin Pattern shop incharge HR (ADMININISTRATION) Moulding & Process control in -charges Melting & Fettling Incharges HR (MATERIALS) Quality Control In charge Packing & Despatch Incharge Stores Maintenance Mechanic al Supervisors & Workers of all departments in a Electrical Producti on Incharge Melting Incharge 106 Fettling Incharge . Malhotra.in.com.  www. Pearson Education 107 .Chakrabarti. 2005 PHI Learning Private limited.REFERENCES:  www. Tata McGraw-Hill  NareshK. A. Official website of Aruna alloy steels private limited.arunasteel. Government of India.steel.K. “Marketing Research Fifth Edition”.Chase.nic.  Richard B.  26th Annual SEEANZ Conference Proceedings Paper. “Operations Management for Competitive Advantage Ninth Edition”. Ministry of Steel. Madurai.  Casting Technology and Cast Alloys.