7/1/00AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components STEEL CASTINGS Specification M-201-00 Adopted: 1923; Revised: 1984, 1993, 2000 M-201 1.0 SCOPE These specifications cover carbon and alloy steel castings for locomotive and car equipment and for miscellaneous use graded as A, B, B+, C, D, and E. AAR Specification M-201 provides for all castings unless another AAR specification for a particular product provides for a variation. 2.0 BASIS OF PURCHASE Grade A castings shall be furnished unannealed, annealed, or normalized unless otherwise specified by the purchaser. Grades B and B+ castings shall be furnished normalized or normalized and tempered. Grade C castings shall be furnished normalized and tempered or quenched and tempered. Grades D and E castings shall be furnished quenched and tempered. 2.1 At the purchaser’s request, a certification will be made the basis of acceptance. The certification shall include a statement that the material has been manufactured, sampled, tested, and inspected in accordance with, and meets the requirements of, all applicable provisions of these specifications. Each certification furnished shall be signed by an authorized agent of the supplier or manufacturer. 3.0 RECORDS The manufacturer shall maintain for 15 years records of the mechanical and chemical test reports covering the heats representing the purchased castings. These records will be made available to the purchaser upon request. MANUFACTURE 4.0 PROCESS The steel may be made by one or more of the following processes: Open hearth, electric furnace, crucible, converter, or basic oxygen. 5.0 HEAT TREATMENT Castings shall be cleaned sufficiently to respond to heat treatment. Internal cavities shall not be blocked by molding material. They shall then be treated according to the following procedure appropriate to the requirements of paragraph 2.0. 5.1 Heat Treatment 5.1.1 After pouring, castings shall be allowed to cool to a temperature below 1,000 °F (538 °C) prior to heat treatment at a rate that will not be injurious to the castings. 5.1.2 Full Annealing The casting shall be heated to the proper temperature above the transformation range for the required time to achieve complete austenization and to refine the grain structure. The casting shall then be allowed to cool slowly in the furnace. Unless otherwise required by the purchaser, the manufacturer has the option of normalizing instead of full annealing, where full annealing is specified. 5.1.3 Normalized steel castings shall be processed in the following order: 5.1.3.1 Heat to the proper uniform temperature above the transformation range and hold for the proper time to achieve complete austenization and to refine the grain structure. 5.1.3.2 Withdraw from the furnace and cool in still air until temperature is below 700 °F (371 °C). B–4 7/1/00 but not less than 600 °F and hold for the required time.1 Heat to the proper uniform temperature above the transformation range and hold for the proper time to achieve complete austenization and to refine the grain structure.3 Temper by reheating to the proper uniform temperature below the transformation range. Records of time-temperature charts. 5.3 Temper by reheating to the proper uniform temperature below the transformation range.3.2 Withdraw from the furnace and cool in still air until castings in their entirety are at least 100 °F below tempering temperature. 5. The location of the test lugs shall be such that when removed by the inspector. These documents are to be presented and reviewed as part of the Foundry Approval process and are intended to ensure that products are properly heat treated.3 At the manufacturer’s option.4. The manufacturer is required to develop and document heat. Remove from the furnace and allow to cool at any desired rate.5 Quenched and tempered steel castings shall be processed in the following order: 5.5. high. This submission must ensure that the intent of this specification is being complied with. 5.1.4. coupler bodies. and 1/2 in.1.2 Withdraw from the furnace and while castings are above the transformation range. provided a detailed proposal is submitted in writing to the AAR for approval. and pyrometer calibrations will be maintained for 3 years and made available to the purchaser upon request. Grades B and B receive a subsequent tempering. yokes. at least two and not more than four test lugs shall be cast on all castings 150 lb and over and on such castings less than 150 lb as required by the purchaser.1. 5. All castings prone to cracking after quenching shall be tempered as soon as necessary to prevent cracking. 5. If inspection of the test lug indicates that the casting has not been heat treated.4 Normalized and tempered steel castings shall be processed in the following order: 5. process control procedures.1 Heat to the proper uniform temperature above the transformation range and hold for the proper time to achieve complete austenization and to refine the grain structure. 5. including 1) type of product. 2) the prescribed heat treatment. the casting will be heat treated. draft gears.5. the heat numbers) of the castings on the load. remove from the furnace.1. 7/1/00 B–5 . 3) the serial numbers (if not available.2 Heat Treatment Documentation These provisions apply only to truck frames. Furnace temperatures for heat treatment shall be controlled by pyrometers having associated recording equipment that produce time-temperature record charts that are identified by date and furnace number. treating standards that describe the processes.1. they shall indicate if the casting has been subjected to heat treatment.5. Hold for the required time. and 5) actual time of heat treatment. thick where it joins the casting.1. or 5/8 in. subject to rapid cooling by suitable liquid medium to a temperature substantially below the transformation range. wide. 1 in. furnace log sheets.1. 4) the identification number of the test coupon or coupons charged with the load. or cushion units. The standard test lug shall be 1 in.1. and allow to cool at any desired rate.3 Test Lugs For all castings. bolsters. Alternate procedures will be considered.7/1/00 M-201 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components castings specified as normalized may 5. 5. but not less than 800 °F. Pyrometers shall be calibrated every three months. A log sheet for each load of castings heat treated should show all information pertinent to each heat treat load. and record keeping requirements. 5.4. but in no case shall the time between quenching and tempering exceed 8 hours.1. 04 1. manganese.32 Minimum Hardness.2.2 The content of elements other than those designated in paragraph 6. 6. If drillings are used.1 Chemical Composition The steel analysis shall not exceed the following: Carbon. 6.3.85 0. D.2 Frequency of Test Following satisfactory Jominy test results for 10 consecutive heats.1. maximum percentage Sulfur. B–6 7/1/00 . 6.1.1 shall be selected by the manufacturer to obtain the physical properties specified.31 to 0. B.90 0. maximum percentage Grades A.2 Hardenability 6.1 Ladle Analysis An analysis of test samples taken during the initial 25% of the castings poured from each ladle must be made by the manufacturer to determine the percentage of carbon.1 Grades A. maximum percentage Phosphorus. and intentional alloying elements.3 Chemical Analyses 6. 6.2 End of Heat Analysis For each heat of steel. the manufacturer shall conduct one Jominy test at least once every month for Grades D and E steel. sulfur. & B+ 0. to a maximum of 1. silicon. Rc 30 33 35 6.04% manganese above the maximum specified will be permitted. they must be taken at least 1/4 in. maximum percentage Silicon. Appendix III.04 1. except for coupler locks.32 1.1.04 0.1 Grades D and E Steel Composition of steel. from the quenched end for the carbon composition as follows.3. or taken after the pouring of.7/1/00 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components M-201 6.2%. 6.50 Grades C.25 to 0.2. phosphorus.32 0.04 0. The result of this analysis shall be reported to the purchaser or purchaser’s representative upon request and shall conform to the requirements of paragraph 6. and B+ Steel For each reduction of 0.3 Hardenability Calculations The Ideal Critical Diameter (DI) shall be calculated for each heat of quenched and tempered steel in accordance with ASTM Designation A255. The results of this analysis shall be reported to the purchaser or purchaser’s representative upon request and shall conform to the requirements of paragraph 6.1. latest revision. The calculated DI value shall be shown as information on the report of mechanical and chemical tests as defined as paragraph 3. a sample representing the last metal going into.01% carbon below the maximum specified.30 0. shall produce in the standard Jominy test the minimum hardness at 7/16 in.2. & E 0. the last acceptable casting must be used by the manufacturer to determine the percentage of manganese. beneath the surface of the test ingot. maximum percentage Manganese.0. If drillings are used.25 0. an increase of 0. B.0 CHEMICAL PROPERTIES AND TESTS 6.50 6. based on the initial composition: Percentage Carbon up to . 7/1/00 M-201 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components they must be taken at least 1/4 in. Batch process heat treat furnace load is defined as all the castings in the heat treat furnace of the same grade of steel. B 70 38 24 36 Gr. Specimens are to be removed from coupons produced per paragraph 7. E 120 100 14 30 7.2 The steel used for the casting shall conform to the following minimum requirements.4 Check Analysis An analysis may be made by the purchaser from the broken tension test specimen or from a casting of each heat.2. Continuous process heat treat furnace load is defined as all the castings of the same grade of steel that pass a given location in the furnace during the period of one heat treating cycle. Specimens to be removed from coupons produced per paragraph 7. 7.0 MECHANICAL PROPERTIES AND TESTS 7. Drillings for analysis shall be taken not less than 1/4 in. D 105 85 17 35 Gr.1 Tensile Test Specimen Coupons 7.4 If the percentage of elongation of any tension specimen is less than that specified. 7. Records shall be maintained for 2 years only. round (13 mm) 2-in. beneath the surface and shall be taken in such a manner as not to impair the usefulness of a casting.1. excluding flawed specimens. beneath the surface of the test ingot. coupons shall be either cast attached to the casting or the gating system or produced from keel blocks and prepared in accordance with ASTM Designation A370. % Reduction of area. Specimens to be removed from coupons produced per paragraph 7. 7.1. If a test specimen shows a defect during machining or exhibits flaws before or after testing.2. Each heat treat furnace load shall include at least one test coupon of the same grade of steel and have its mechanical properties determined and recorded. a retest is allowed.1.1 Test shall be conducted in accordance with Standard Methods and Definitions for Mechanical Testing of Steel Products. ksi Elongation in 2". 7/1/00 B–7 .2. it shall be discarded and another specimen substituted. in the same manner as the castings they represent. Grade A Unannealed Tensile strength.2. 7.1.2 Tension Test 7. B+ 80 50 24 36 Gr.1. from the center of the gauge length as indicated by the gauge marks on the specimen before testing. 7.3 Each melt shall be tested for mechanical properties after heat treatment. 7.1.1.3 The manufacturer shall test specimens from melt heats and record results. (50 mm) gauge length specimens as illustrated in that specification.1. using 1/2-in.2 The process used for the manufacture of keel blocks shall be representative of the manufacturer’s normal process methods. 6. One specimen per heat for each grade of steel shall be tested.1.1 At the manufacturer’s option. ksi Yield point. % 60 30 22 30 Annealed or Normalized 60 30 26 38 Gr.1. and any part of the fracture is more than 3/4 in. The chemical composition thus determined shall conform to the requirements specified in paragraph 6. C 90 60 22 45 Gr. ASTM Standard A370. The coupons from each melt shall be heat treated with castings of the same grade. The results shall meet the following minimum requirements at the stated temperatures: Cast Steel Grades B and B+ Grade C (NT) Grade C (QT) Grade D Grade E Temperature (°F) +20 0 –40 –40 –40 Energy (ft lb) 15 15 20 20 20 7.4.3.3. 7.1.2. A test consists of determining the average energy absorbed from three impact specimens from the same heat. 7.1.4 The record keeping requirements and test frequency are the same as specified in paragraph 7.5 At the time of purchase.4 As a manufacturer’s alternative.1.3.2.1 The Dynamic Tear Test shall consist of determining the average energy absorbed from three specimens from the same heat.3. which shall be a minimum of 50 ft lb at the temperatures specified in the table in paragraph 7. 7. impact properties may be determined by use of the Dynamic Tear Test (ASTM E604) or the Nil Ductility Transition Test (ASTM E208). 7.3. Both specimens shall exhibit “no-break” performance. excluding flawed specimens.3 Dynamic Tear and Nil Ductility Test Temperatures shall be: Dynamic Tear and Nil Ductility Test Temperatures Cast Steel Testing Temperature (°F) Grades B and B+ +60 Grade C (NT) +60 Grade C (QT) –60 Grade D –60 Grade E –60 7.6 Results of testing must show compliance with the requirements of paragraph 7. 7.3 Impact Test 7. Specimens to be removed from coupons produced per paragraph 7.4.2 prior to shipment of finished castings. 7.2 Impact tests shall be conducted in accordance with the Standard Methods and Definitions for Mechanical Testing of Steel Products.4.4.4.1. 7.2 The Nil Ductility test shall consist of testing two specimens at the temperatures specified in the table in paragraph 7.3.3. specimens may be cut from castings (excluding flawed specimens) and must have at least 80% of the tensile and yield properties established in paragraph 7. including chemistry of that heat.2.5 A check test may be made by purchaser from a casting at purchaser’s expense. Specimens to be removed from coupons produced per paragraph 7.1 The steel shall possess impact properties determined by testing standard Charpy-V-Notch Type “A” specimens prepared as illustrated in Figure 11 in ASTM Standard A370.3. B–8 7/1/00 .1.3. Results of this testing shall conform to the minimum values specified in paragraph 7.3. ASTM Standard A370.1.3.7/1/00 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components M-201 7.3 The manufacturer shall test specimens from melt heats and record results.3.3. Specimens to be removed from coupons produced per paragraph 7.4. 7.4.2. Frequency of these tests shall be one heat per week per grade of steel obtained during the pouring of the last 25% of heat.3.2.3.3. as required in paragraph 7. sound metal remaining between the bottom of the weld groove and the opposite side of the casting wall in areas where welding cannot be accomplished from both sides of the casting wall. 7/1/00 B–9 . or equivalent. in the position welding is to be performed. if no drawing has been provided. 12. Where defect continues through the casting and is inaccessible from both sides and unless prohibited by specific component specification.1.0. 9.0 RE-HEAT TREATMENT If the results of the physical test lot do not conform to the requirements specified. the physical properties. WORKMANSHIP AND FINISH 10. must be within a Brinell Hardness range as follows: Material Grade Identification Grade A Grades B and B+ Grade C Grade D Grade E BHN Range 108–160 137–208 179–241 211–285 241–311 Testing to be done on a surface that has been ground to remove decarburization in accordance with ASTM A370. 11. except as provided for in product specifications.7/1/00 M-201 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components 7.3 Defects may be repaired by using a metal-electrode arc welding process that will result in sound weld deposit having. 12.2 Welders shall be qualified and use procedures under the welder qualification procedure contained in AWS 15. in the heat-treated condition.1 Weld Repair of Defects The entire defect must be removed prior to weld repair. The area to be welded must have the sides contoured to provide for the application of a sound weld.0 WORKMANSHIP All castings shall conform to the dimensions on drawings furnished by the purchaser before manufacture is started. defect may be weld repaired by using a copper backup plate provided the surface is smooth and clean. Maximum depth of repaired area must allow at least 1/8 in. Where a defect continues through the casting wall and both sides of the wall are accessible for welding. will be determined from an extra or spare test coupon cast with and attached to some other casting of the same heat. minimum mechanical properties equal to the requirements for the parent metal.0. SMALL ORDERS In case of small orders for castings weighing over 180 lb where the size of the order and the available pattern and foundry equipment are such that not more than five castings can be cast in one heat. or to the dimensions predicated by the pattern supplied by the purchaser. the manufacturer may re-heat treat such lot not more than twice. Post-weld heat-treatment requirements are outlined in the product specification for the component involved.4 Hardness Cast steel components. 8.0 WELD REPAIR OF DEFECTS 12. the casting shall be welded from both sides using a double “V” or a “U” contour weld. Welding may be performed in either the non-heat-treated or heat-treated condition. 12. and retests shall be as specified in paragraph 7.0 FINISH The castings shall be free from injurious defects and shall be thoroughly cleaned when offered for inspection.0 NUMBER OF TESTS. or to individual product specification. C. at all times while the work on the contract of the purchaser is being performed. E8016. the weight agreed upon between the purchaser and the manufacturer shall not vary more than 5% above or 3% below the determined weight of the castings.7/1/00 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components M-201 12. E11018. E13016. free of charge. E7018. will be rejected. E8018. Localized preheating is acceptable. and. 12.6 For Welding Grades B and B+ Steel Castings If shielded metal arc process is used. an electrode of the AWS/ASTM Class E10015. or equivalent. E6018. E7016. E12018.4 Grade A.0 INSPECTION 15. The manufacturer shall afford the inspector. Such tests shall be made at the expense of the purchaser. 15. D.5 For Welding Grade A Steel Castings If shielded metal arc process is used. E8015. and welding shall be accomplished while the casting is maintained at a temperature above 300 °F. If local preheating is performed. E8018. INSPECTION AND REJECTION 15. VARIATION IN WEIGHT 14. or equivalent. E8016. Tests and inspection shall be made prior to shipment at the place of manufacture unless otherwise specified. E9016. 12. the casting shall be uniformly preheated to a temperature between 300 °F and 600 °F. 12. or equivalent may be used. the purchaser’s initials shall be legibly cast on all castings.3 Rejection Material represented by samples that fail to conform to the requirements of these specifications.0 VARIATION IN WEIGHT When not covered by individual product specification. all reasonable facilities and necessary assistance to satisfy the inspector that the material is being furnished in accordance with these specifications.2 The purchaser may make tests to govern the acceptance or rejection of the material in purchaser’s laboratory or elsewhere. E11016.8 For Welding Grade D Steel Castings If shielded metal arc process is used. or equivalent. E10018. B–10 7/1/00 . 12. the electrode shall be E6015. B+. E10016.7 For Welding Grade C Steel Castings If shielded metal arc process is used. E12016. to all parts of the manufacturer’s works that concern the manufacture of the material ordered. the pattern number and grade. 13. the electrode shall be a low hydrogen coated type as follows: for Grade B—AWS/ASTM Class E7015. 12. or equivalent. 15. the manufacturer’s identification mark. the electrode shall be a low hydrogen coated type AWS/ASTM E11015.0 MARKING When marking requirements are not covered by individual product specification. or equivalent may be used for higher mechanical properties after heat treatment. The temperature shall not exceed 600 °F to avoid the possibility of warping.9 For Welding Grade E Steel Castings The welding materials used for the repair of defects in Grade E steel castings shall be AWS/ASTM Class electrode E12015. E13015. At the option of the manufacturer. AWS/ASTM Class E9015. the electrode shall be a low hydrogen coated type. when specified. E6016. E9018. E13018. or equivalent may be used. B. for Grade B+—AWS/ASTM E8015. or E castings shall not be welded while the temperature of the casting is below 40 °F.1 The inspector representing the purchaser shall have free entry. 15.4 Material that.5 AAR Representation In addition to the purchaser’s representation. and the manufacturer shall be notified. test. This access is for the purpose of providing assurance that industry standards are being maintained.7/1/00 M-201 AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components 15. an AAR official representative shall have free entry at all times to all parts of the manufacturer’s works that concern the manufacture. The manufacturer shall afford the AAR representative all reasonable facilities to ensure that materials are being furnished in accordance with these specifications. subsequent to test and inspection at the foundry or elsewhere and its acceptance. 7/1/00 B–11 . shows injurious defects will be rejected. and inspection of materials for use in Interchange Service.