Is 6745 (1972)_ Method for Determination of Mass of Zinc Coating on Zinc Coated Iron and Steel Articles

इंटरनेट मानकDisclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. “जान1 का अ+धकार, जी1 का अ+धकार” “प0रा1 को छोड न' 5 तरफ” Mazdoor Kisan Shakti Sangathan Jawaharlal Nehru “The Right to Information, The Right to Live” “Step Out From the Old to the New” IS 6745 (1972): Method for determination of mass of zinc coating on zinc coated iron and steel articles [MTD 24: Corrosion Protection] “!ान $ एक न' भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह” है” ह Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” . 1) UDC 669. I N D I A N S TAN DAR D S MANAK BHAVAN.rporating Amendment No. IS : 6745 • 1872 ( R••rnrmed t 81M ) Indian Standard METHODS FOR DETERMINATION OF MASS OF ZINC COATING ON ZINC COATED IRON AND STEEL ARTICLES Seventh Reprint JULY 1998 (Inco.1-4 : 531..58 : 669.753 © Copyright 1979 B IJ REA U 0... 9 BAHADUR SHAH ZAFAR MARG NEW DELHI 110002 Gr 3 Marcil 1973 . Delete and incorporate the following Note thereunder: 'Note The time required for stripping wlll vary with the coating thickness and generally should not exceed 1 minute.' (SMDC 28) Printed at Printograph. .2. clause 5. _Ill.3. New Oelhi (I~ DlA I. The time of 1 minute maximum 1s to ensure that no dissolution of iron takes place. last sentence) . 2 JANUARY 1987 TO 15:6745-1972 METHODS FOR DETERMINATION OF MASS OF ZINC COATING ON ZINC COATED IRON AND STEEL ARTICLES (Page 8. 3 MAY 1989 TO IS : 6745 -1972 METHODS FOR DETFRMINATION OF MASS OF Z. (SMDC 28) Printed at Printograph. line 2 ) .INC COATING ON ZINC COATED IRON AND STEEL ARTICLES (Page 5. Substitute '50 mm' for 4300 mm'. New Delhi f1NDIAt .3. AMENDMENT NO. clause 3. Z.. 111.: 572hX47 .4 OCTOBER 1996 TO IS 6745 : 1972 METHODS FOR DETERMINATION Of" MASS OF ZINC COATING ON ZINC COl\TED IRON AND STEEL ARTICLES ( Page 5.5 4383 "For further details of the dimensions refer 3.2.2 of IS 397S : 19R5. Printed at I'rintogruph.1 ) .. AMENDl\JIEN1' NO.M2 M= xK M2.0 3._._-_. New Delh. M2 =1l13SS of the stripped test piece in g.4 27.-._-.-_. = 1l1aSS of the original test piece in g.2. M. The wire shall also include the formed wires as per .2... and The value of the constant K for different sections shall be as under: Type oflVire Dimensionis) Constant Round All Sizes d x 1965 A B C R Formed" 4.8 10 2571 6.'-' Substitute the following for the existing: 'S.' (Page 7.2 ) -Insert the following note «It the end of the clause: 'Non.2 of IS 3975 : 1985.3 1.' (MTD 20) .1. . clause 5.1 5._-_. where M =1113SS of zinc coating in g/n12 of surface.1 Calculation Mt.. . clause 3._ .. 1... '-'-~--------_ _----_.4 0. A. K. AGRAWAL Hirrdust an Aluminium Corporation Ltd.ANEY Krips Consultants.CUATI'ERJ~E (Alternate) SURI P. 9 BAHADUR SHAH ZAFAR MARO NEW ostm 110002 .(. CHAKRAVARTY The Tata Iron and Sled Co Ltd. C. R. Williams Ltd. D. SRINIVASAN ( Alte'TllJle) Sl-IRI C. SONI ( Alternate) SHRr VJJAY. IhIATTACHA1~ YVA Directorate General of Po~~ and Telegraphs Depart- mcnt. SMI)C 28 Chairman RL'p. Bombay SURI N. K. Howrah DR V. ALTEKAR National Metallurgical Laboratory (CSIR ). 15: 6745-1J72. N. M. ADINARESH RAO National Metallurgical Laboratory (CSIR) Jamshedpur SURI P. Indian Standard METHODS FOR DETERMINATION OF MASS OF ZINC COATING ON ZINC COATED IRON AND STEEL ARTICLES Ifot-Dip Metallic Coatings Sectional Committee. T. K. MURTHY Indian Aluminium Co Ltd. B. Chandigarh SURf S. Jamshcdpur !Y1embers SHRI v'. Jal'lllhedpur SHRI V. Bombay SHRI M. Bombay DR R. Jarnshedpur SHRr S. K. J. C.'d on page 2 ) BUREAU OF INDIAN STANDARDS MANAK BHAVAN. NARASIMHAN ( Alt. K. Jarnsht'dpur ~1AJ.. K. S. K. Keen. DR M. L.. KASIIYAP Special Steels Ltd. MURANJAN ( Alternate ) SURI D. PARTIIASAR'fIJl Indian Hot Dip Galvanizers' Association. SEN ( Alternate ) SHRI C. RAo Minist~ of Defence ( DCl ) ( Contint. C. N.esenling PROF V. RAKSHIT ( Alternale) SIIIU B. BALASANKAR ( AllernaU) SHRI A. GUPTA Zenith Steel Pipes Ltd. Calcutta Saar K. G. VI::NKATARAMAN (Alternate) . NAIR The Indian Tube Co Ltd.RN M. Calcutta SHRt·"'. KRIPAl. FINNEY Devidayal Cable Industries Ltd. Bombay SIiRI S. BAGCHI National 'rest House. DEWAN The Tinplate Co of India Ltd. c. .HOTRA The Metal Box Company of India Ltd. R.KAPUR Guest. Jarnshedpur DR S. BALI Hvdel Design Directorate. Calcutta SURJ B. Rcnukoot SHRI N. CAPRIHAN ( Alternate ) . S. SURf C. Calcutta SIIRI ~\. MAI-IAJAN TIle Indian Steel and Wirt~ Products Ltd.rna!e) Snal MOHAN PRASAD Hindustan Steel Ltd (Rourkela Steel Plant) Rourkela SHRI S. New Delli SIIRI N. J. P. I I. Bombay SHRI C. DESIGNS AND STANDARDS ORGANIZATION.erllary SHal S. AJOOANKAR ( Alternate) WORKS MANAGER. lSI . LUCKNOW ( Alternate) SaRI R. D. lSI (Ex·offieio Member) Deputy Director (Strue &t Met) S. SJNGH ( Alternate) . R. L.··1S. K. SENGUPTA Electrical Manufacturing Co Ltd. N. BALI Deputy Director (Met). F.pr. RESEARCH. VARMA Hindustan Kokoku Wires Ltd. SRIVASTAVA.6745 • 1972 ( C.nlinUldfrom PtJIl 1 ) Members R. CHITTARANJAN CHEMIST & METALLURGIST. SURI K. Calcutta SHRI S. K. New Delhi SHRI D.:. SHROFF Kamani Engineering Corporation Ltd. Director General.sl1Iting SaRI R. CHJTTARANJAN Ministry of Railways LOCOMOTIVE WORKS. bolts and nuts. FOREW ORD 0.4 For the purpose or deciding whether a particular requirement of this . fi)rgin~s etc. Assistance has abo bceu derived from the following publications: BS 443 : 1969 Specification for galvanized coatings on wire. British Standards Institution. stripping method has been prescribed for ~alvanizcd articles. Dirept method of determining the mass of zinc coating by weighing the articles before and after galvaniz- ing and subtracting the first mass from the second and dividing the resul t by surface area has not been inc! udcd in the standard as it gives a slight. the final value. UK.uaudurd is complied wit h . metallic coated products. ~\S"rNl Part 3 1970 Steel sheet. American Society for Testing and Materials. 0.ly lower results. rolled steels.1 This Indian Standard was adopted by the Indian Standards Institution on 20 December 1972. tube.2 For determining the mass of zinc coating.1972 Indian Standard . wire and other iron and ~t('~~l articles. observed or calculated. shall be rounded off in accordance vvi~h IS: 2·1960*. USA. express- irur the results of a test or analysis. Volumetric method has been included fordetcrmining the mass of zinc coating on steel wir e as this method gives reasonably accurate results for routine testing.3 The test' methods have been based on the test procedures generally followed in the country in this field. 0. castings.1 This standard covers the plocedurc~ for determination of mass of coating (In Ztl\C coated sheet. 1. bar. such as sheet and strip. after the draft finalized by the Hot-Dip Metallic Coatings Sectional Committee had been approved by the Structural and Metals Division Council. SCOPE 1. The number of significant places retained in the rounded off val ue should be the same as that of the specified value in this st. wire.uidard. IS : 6745 . 0. METHODS FOR DETERMINATION OF MASS OF ZINC COATING ON ZINC COATED IRON AND STEEL ARTICLES o. rod. wire. 3 . *Rules fur rouudiug off numerical values ( revised ). strip. UALITY OF REAGENTS 2. NOT.1.1 Unless otherwise specified. b) Single Spot Test . Q.C Pure chemicals' shan mean chemicall that do Dot contain impuritiea which afFect the results of analysis.1. pure chemicals shall be employed in tests and distilled water (see IS: 1070.1. • Specification for water. J. show- mg a minimum coating mass. the following formula may be used to calculate the mass of coating: M == M 1 . . 3. For sheets galvanized by the continuous method. M.1. and t == thickness of stripped sheet in mm.1960*) shall be used when the use of water as a reagent is intended.d). or the test piece shall be taken from an arbitrary place within at least 100 mm away from the top or bottom and at least 50 rom away from the side. one test piece out of the three test pieces taken by the same method as for the triple spot test.f1 == mass in g of galvanized test piece.In this test. shall be selected.1 The test piece shall be taken by one of the following methods sub- ject to purchaser's requirements: a) Triple Spot Test . three test pieces shall be taken at the end part of the coil. This clause relates only to the preparation of test pieces from the samples thus taken. SAMPLING 3. M s == mass in g of stripped test piece.Three test pieces either square or circular to size 50 X 50 mm or 50 mm dia shall be taken one from the centre and two from the opposite ends of the diagonal line. 3. 3.IS I 6745 • 1972 2. X t X 7 860 I where M =-·mass of zinc coating in g/m l of sheet. such as described in 3.2 When it is not possible to obtain a test piece of measurable area. from corrugated sheet.1 Galvaaized Sheet 3. 4 . distilled quality ( "l1is. at least 100 mm away from the top or the bottom and at least 50 mm away from the side.0 Sampling of the material shall be done in accordance with the relevant material specification. one from the centre and two from the location at least 50 rom away from each side. . the test piece.2. For steel shapes. 3. at least 100 Bun away from top or bottom and at least 50 rnm away [r.1 Galvanized Rolled L~teel. three test pieces shall he taken from centre and both ends. I n the case of stranded or armoured wire. If desired by the purchaser.)O'1 the side. 3. Where continuous length is not avail. 3.For steel plate. pipe fittings.3 Galvanized Tube .plates. one from the centre of the plate and the other two from opposite locations of the diagonal line. able. cast iron and malleable cast iron products. Before cutting.1' The sample length of the wire shall be cut from one or both ends of the coil under test. three test pieces shall he taken from centre and both ends. as in the case of steel sheet.3. 3. subject to the purchaser's requirements: a) The test piece shall be of the size and the coated area of 100 ern". or wire which has undergone any other similar process. fabricated structures.2 Galvanized Wire . assembled products.These iucludc the following: a) Rolled Steel --_. shorter tt~lOit piece totalling over 300 mrn but preferably 600 turn shall he used.4 Galvanized Articles Other than Sheet. it is not necessary to use a specific length.2. bars.1972 3. h) Bolts and Nuts . For steel bars and flats. 300 nun in length from both ends of the product shall be discarded. shall be taken. holts and threaded articles including nuts and washers.4. c) Casting and Forging-.the sample. sample may be cut from each selected coil or reel of strand or cable or from any portion of such wires. flats. IS : 6745 . etc. Wire and Tube . and b) The test piece may be taken from the original material cut to a sui table size and galvanized in the same manner as the -product. Portions of wire which arc obviously damaged shall not be used for sample.2 The test piece of galvanized wire may be of any length over 300 mm but preferably 600 III In.A tubular test piece of 100 mrn in length shall be tukc. etc. eliminating 50 nun from both ends. s . eliminating 50 mm from both ends.cast steels. 1) Triple 8/)01 Test .The test piece shall be cut from the galvanized prod !_lct by one of the following methods. care should be taken to avoid damage in preparing. three test pieces. Since the specific ~ravity of steel is known.i from each end of product.. structural shapes. When the evolution of hydrogen ceases or a few bubbles are being evolved.For triple spot test. When the product is too large or inconvenient in handling. prepare the stripping solution by adding 5 rnl of the solution prepared under 5. 5.1 Dissolve 20 g of antimony trioxide (ShaO a ) or 32 g of antimony trichloride (SbOI. after it has been galvanized in the same bath along with the material it represents.2 Procedure 5. too. then with alcohol and finally dried thoroughly.6 CastlDg_ and Forgings .IS I 6745 • 1972 2) Single Spot Test .Actual product may be used as a test piece or the test piece may be taken by one of the following methods with the consent of purchaser: a) Should the material happen to be too large. b) Alternatively.2.1.) in 1 000 ml of concentrated hydrochloric acid ( sp gr 1-16 ).1 Strippiag SoludoD 5.pnring test piece is also applicable in case of articles whose surfa area may be difficult to determine.2 Immediately before test. heavy or incon- venient in handling.5 Galvanized Bolts aDd Nats .A product as manufactured shall be used as the test piece but the determination shall be made on the portion of the article that does not include any thread.1 The test pieces shall be washed with solvent naphtha. a suitable piece shall be cut off from the original product to make a test piece.One test piece presenting a minimum zinc coating out of the test pieces taken for triple spot test or one taken arbitrary from place other than close to both ends shall be selected. 4. weigh three test pieces together to 0·01 g. 5.1. a suitable piece shall be cut off from the product to make a test piece. Immerse one test piece at a time in the test solution. This method of pre. wiped off well with 6 . shorter piece of the same section and of the same steel composition not less than 90 em long may be used as test piece. 3. CLEANING OF TEST PIECE 4. the test pieces shall be taken out. trichloroethylene or any other suitable organic solvent. 3.1 to 100 ml of concentrated hydrochloric acid (sp gr 1·16). STRIPPING METHOD 5.1. Mix well. washed in water. 5.1 Galvanized Sheet. X d X 1 965 M1 where M = mass of zinc coating in g/ro l of surface. NOTE 2 .1.The time required for stripping will vary with the coating thickness but should not exceed one minute. Ms = rnass in g of the stripped test piece.1 Calculation where M = mass of zinc coating in g/ml of surface. 5. Calculate the mass of zinc coating/unit area of the surface by dividing the difference in mass in grams before and after stripping by the area of the test specimen in square metres. Then measure the diameter to 0'01 mm at two places at right angles to each other of the same location to obtain the average value. IS I 6745 . M" == mass in g of the stripped test piece. until the time for stripping becomes inconveniently long.2.. the average mass of zlnc coating aa obtained from three test samples shall be reported.2.The Same solution may be repeatedly used and without further addition of antimony chloride solution.2 Galvanized Ht . use formula given in 3. wipe off well with clean soft cotton cloth. NOTE 1 .The lame solution may be repeatedly used and without further addition or antimony chloride solution.In case of triple spot test. until the time for stripping becomes inconveniently long. fully dry and weigh again to within the nearest 0'01 g. it shall be either bent or coiled to permit complete immersion in the test solution. When it is not possible to obtain a test piece of measurable area. the temperature of the test solution shall not exceed 38°C. M 1 = original mass in g of the test piece.2 to calculate the mass. 7 .2.2. Mt = original mass in g of the test piece. wash in running water.1. 5. ·e . The number of specrmens immersed at anyone time shall not exceed three per 100 ml of the solution. and A = coated area of the original test piece in mml • NOTE 1 .Weigh the clean test piece to 0'01 g. 5...2. NOTE 3 . fully dried and weighed again.1 Calculation M == Afl -M. When the evolution of hydrogen ceases or a few bubbles are being evolved.During the test. 1972 clean soft cotton cloth.2.1. NOTE 2 . When the test piece is too long for the container. Calculate the mass of coating in g/ro l as in 5. take out the test piece. and d = diameter of the stripped test piece in mm. 1. M 2 == mass in g of stripped test piece. 5. and t == thickness of the stripped test piece in mm. to the nearest 0'1 g and for masses over 1 000 g.same as in 5. weigh.Wei~h the cleaned test piece whose mass is less than 200 g nearest to 0'01 g.2.2 Reagents . 'and only a few bubbles are being evolved. The most suitable length of the test piece 8 .1.1.1 Outline of ~he Meth.The apparatus should consist of a 100-ml glass burette fitted with a stopcock at" the top and the bottom and connected at the bottom with a rubber tube to a reservoir. The apparatus set up for the commencement of a test is shown in Fig. This requires about 15 to 30 seconds except in the case of sherardized coatings which require somewhat longer time. 6. 1. 6.3.Cut accurately a test piece of required length from a sample of wire.1 For test piece of uniform thickness of base metal. the accuracy of weighing shall be nearest to 0'5 g. of determining the mass of coating depends on the fact that a metal dissolved in acid always releases a quantity of hydrogen in stxict proportion to the amount of metal dissolved.2.3 Apparatus . After ~ighing immerse each test piece singly in test solution prepared in 5. such as a piece "of plate or pipe.1 . M 1 = original mass in g of test piece.1.3 Article: Other than Sheet and Wire .IS : 6745 • 1972 5. X == ------.nd allow to remain there until the violent evolution of hydrogen ceases.The ~olumetric method.3 Calculation M M 1 . 6. 6. determine the average thickness of the test piece to the nearest 0'25 mm and calculate the mass of zinc coating as in 5.3.od . t X 3 930- M2 where M == mass of zinc coating in g/m 2 of surface. for test : piece whose mass is between 300 to 1 000 g.. DETERMINATION OF MASS OF COATING ON WIRE (BELOW 5 mm IN NOMINAL DIAMETER) BY VOLUMETRIC METHOD 6.4 PreparatioD of Tp8t Piece . 5. 1. has ceased.3 The zinc coating rapidly dissolves and liberates hydrogen and the test is continued until evolution of hydrogen. 5 rom as with larger diameters. Above 1·50 to 3-00 100 Above 3-00 50 6.6.te scale. Nominal Length of Test Piee« . The lengths given below will be found convenient.6. but for a few fine bubbles.4 When the test is concluded.6.Open lower stopcock B to eject the ~st piece. 9 . Lift the reservoir C from its supporting ring and place alongside the burette until the levels of the acid reagent in the burette and the reservoir are equal as shown in Fig. However.2 To carry out a ':. when the volume of hydrogen is read off on the burc. 6. 6. 6. 6. 6.5 Cleamag of Te.6.6. . 2.The test piece may be cleaned al described in 4.6.6 Wash the stripped wire. diameter .t Piece .5 This method is usually limited to wires of maximum diameter.6 Procedare 6. open the upper stopcock A and draw all acid reagent from the burette by lowering the reservoir C 11> a position below lower stopcock B. Drop the sample of the specified length into the burette and close the upper ~topcock A immediately. 6. Diameter of Galvanized Wire mm mm Above 0-4 to 1-00 300 Above 1-00 to I-50 150.6745. adjust the height of the reservoir C so that the acid reagent ju-t fills the burette up to the stopcock A with the bottom stopcock B closed.1972 dep~nds on. rapid entry Into the burette may be difficult and it may be more convenient to drop the short piece simultaneously through the stopcock. wipe it dry and measure the diameter to 0-01 mm at right angle to each other of the same location to obtain the average value. 15.~here long test pieces are necessary. the size of the burette.1 Pour the acid reagent into the reservoir so that it completely fills the burette leaving a small portion in the reservoir when in the elevated position. problems of test piece preparation and damage to the glass burette may b~ introduced.of wire and expected mass of zmc coating. 1 ApPARATUS FOR VOLUME- FIG.READY I'OR TEST 10 .11.READINO TAKEN TRIC METHOD .1745 -1972 A c FlO. 2 ApPARATUS FOR VOLUME- TRIC METHOD . f -= 929. and I c= the length of the test piece in mm.7 CalculatioD Mass of coating in g 1m. -= 1/ X f d X I where v = *corrected volume -~f hydrogen in ml that would be displaced at O°C and 760 mm mercury pressure. It is a factor obtained on the basis that 343 ml of hydrogen are liberated at O°C and 760 rom mercury pressure by one gram of zinc. lS: 674S. d = the diameter in mm of stripped wire. • Corrected volume should be calculated by using the C Baa equation '.• 1~2 6. 11 . Second Floor. No. AHMEDABAD 380001 550 1348 tPeenya Industrial Area. FARIDABAD 121001 8-28 88 01 Savitri Complex. Princep Street. Gokulpat Market. Unit VI. Ganga Nagar. Sarvodaya Nagar. E9. Bhadbhada Road. Behind Marol Telephone Exchange. 20/9. Sahibabad Industrial Area. 9 Bahadur Shah Zafar Marg. CHENNAI 600113 23523 15 tWestern : Manakalaya. NEW DELHI 110002 Telephones: 323 0131 t 323 3375. Palayam. 832 92 95 MUMBAI 400093 Branch Offices:: 'Pushpak'. KANPUR 208005 21 68 76 Seth Shawan.I. Bangalore-Tumkur Road. IV Cross Road. MUMBAI 400007 3096528 tSales Office is at 'F' Block. Barua Road. P. HYDERABAD 500001 20 1083 E·52. O. 116 G.T.1 Laboratory : Telephone Plot No. C-Scheme. 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