AAR M201 Specification

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

M-201

STEEL CASTINGS Specification M-201-00  Adopted: 1923; Revised: 1984, 1993, 2000 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 2.0 BASI BASIS S OF PUR PURCHAS CHASE E 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. 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, converter, or basic ba sic oxygen. 5.0 5.0 HEA HEAT TREA TREATM TMEN ENT T 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 5.1 Heat Heat Tre Treat atme ment nt 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. 5.1.2 2 Fu Full ll Ann Annea eali ling ng 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, purchaser, the manufacturer has the option of normalizing instead of full annealing, where full a nnealing 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

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

5.1.3.3   At the manufacturer’s option, Grades B and B castings specified as normalized may receive a subsequent tempering. 5.1.4 Normalized and tempered steel castings shall be processed in the following order: 5.1.4.1 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. 5.1.4.2 Withdraw from the furnace and cool in still air until castings in their entirety are at least 100 °F below tempering temperature. 5.1.4.3 Temper by reheating to the proper uniform temperature below the transformation range, but not less than 600 °F and hold for the required time. Remove from the furnace and allow to cool at any desired rate. 5.1.5 Quenched and tempered steel castings shall be processed in the following order: 5.1.5.1 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. 5.1.5.2 Withdraw from the furnace and while castings are above the transformation range, sub ject to rapid cooling by suitable liquid medium to a temperature substantially below the transformation range. 5.1.5.3 Temper by reheating to the proper uniform temperature below the transformation range, but not less than 800 °F. Hold for the required time, remove from the furnace, and allow to cool at any desired rate. All castings prone to cracking after quenching shall be tempered as soon as necessary to prevent cracking, but in no case shall the time between quenching and tempering exceed 8 hours. 5.2 Heat Treatment Documentation These provisions apply only to truck frames, bolsters, coupler bodies, yokes, draft gears, or cushion units. The manufacturer is required to develop and document heat, treating standards that describe the processes, process control procedures, and record keeping requirements. 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. 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. A log sheet for each load of cast ings heat treated should show all information pertinent to each heat treat load, including 1) type of product; 2) the prescribed heat treatment; 3) the serial numbers (if not available, the heat numbers) of the castings on the load; 4) t he identification number of the test coupon or coupons charged with the load; and 5) actual time of heat treatment. Alternate procedures will be considered, provided a detailed proposal is submitted in writing to the AAR for approval. This submission must ensure that the intent of this specification is being complied with. Pyrometers shall be calibrated every three months. Records of time-temperature charts, furnace log sheets, and pyrometer calibrations will be maintained for 3 years a nd made available to the purchaser upon request. 5.3 Test Lugs For all castings, 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. The location of the test lugs shall be such that when removed by the inspector, they shall indicate if the casting has been subjected to heat treatment. If inspection of the test lug indicates that the casting has not been heat treated, the casting will be heat treated. The standard test lug shall be 1 in. high, 1 in. wide, and 1/2 in. or 5/8 in. thick where it joins the casting.

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

M-201

6.0 CHEMICAL PROPERTIES AND TESTS 6.1 Chemical Composition The steel analysis shall not exceed the following: Grades A, B, & B+

Grades C, D, & E

Carbon, maximum percentage

0.32

0.32

Manganese, maximum percentage

0.90

1.85

Phosphorus, maximum percentage

0.04

0.04

Sulfur, maximum percentage

0.04

0.04

Silicon, maximum percentage

1.50

1.50

6.1.1 Grades A, B, and B+ Steel For each reduction of 0.01% carbon below the maximum specified, an increase of 0.04% manganese above the maximum specified will be permitted, to a maximum of 1.2%. 6.1.2 The content of elements other than those designated in paragraph 6.1 shall be selected by the manufacturer to obtain the physical properties specified. 6.2 Hardenability 6.2.1 Grades D and E Steel Composition of steel, except for coupler locks, shall produce in the standard Jominy test the minimum hardness at 7/16 in. from the quenched end for the carbon composition as follows, based on the initial composition: Percentage Carbon

Minimum Hardness, Rc

up to .25 0.25 to 0.30 0.31 to 0.32

30 33 35

6.2.2 Frequency of Test Following satisfactory Jominy test results for 10 consecutive heats, the manufacturer shall conduct one Jominy test at least once every month for Grades D and E steel. 6.2.3 Hardenability Calculations The Ideal Critical Diameter (DI) shall be calculated for each heat of quenched and tempered steel in accordance with ASTM Designation A255, Appendix III, latest revision. The calculated DI value shall be shown as information on the report of mechanical and chemical tests as defined as paragraph 3.0. 6.3 Chemical Analyses 6.3.1 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, manganese, phosphorus, sulfur, silicon, and intentional alloying elements. 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 6.1. If drillings are used, they must be taken at least 1/4 in. beneath the surface of the test ingot. 6.3.2 End of Heat Analysis For each heat of steel, a sample representing the last metal going into, or taken after the pouring of, the last acceptable casting must be used by the manufacturer to determine the percentage of  manganese. 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. If drillings are used, B–6

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

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they must be taken at least 1/4 in. beneath the surface of the test ingot. Records shall be maintained for 2 years only.

6.4 Check Analysis  An analysis may be made by the purchaser from the broken tension test specimen or from a casting of each heat. The chemical composition thus determined shall conform to the requirements specified in paragraph 6.1. Drillings for analysis shall be t aken not less than 1/4 in. beneath the surface and shall be taken in such a manner as not to impair the usefulness of a casting. 7.0 MECHANICAL PROPERTIES AND TESTS 7.1 Tensile Test Specimen Coupons 7.1.1   At the manufacturer’s option, 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. 7.1.2 The process used for the manufacture of keel blocks shall be representative of the manufacturer’s normal process methods. 7.1.3 Each melt shall be tested for mechanical properties after heat treatment. The coupons from each melt shall be heat treated with castings of the same grade, in the same manner as the castings they represent. 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. Batch process heat treat furnace load is defined as all the castings in the heat treat furnace of the same grade of steel. Continuous process heat t reat 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. 7.2 Tension Test 7.2.1 Test shall be conducted in accordance with Standard Methods and Definitions for Mechanical Testing of Steel Products, ASTM Standard A370, using 1/2-in. round (13 mm) 2-in. (50 mm) gauge length specimens as illustrated in that specification. Specimens are to be remov ed from coupons produced per paragraph 7.1.1. 7.2.2 The steel used for the casting shall conform to the following minimum requirements. Grade A Unannealed

Annealed or  Normalized

Gr. B

Gr. B+

Gr. C

Gr. D

Gr. E

Tensile strength, ksi

60

60

70

80

90

105

120

Yield point, ksi

30

30

38

50

60

85

100

Elongation in 2 , %

22

26

24

24

22

17

14

Reduction of area, %

30

38

36

36

45

35

30

"

7.2.3 The manufacturer shall test specimens from melt heats and record results, excluding flawed specimens. One specimen per heat for each grade of steel shall be tested. If a test specimen shows a defect during machining or exhibits flaws before or aft er testing, it shall be discarded and another specimen substituted. Specimens to be removed from coupons produced per paragraph 7.1.1. 7.2.4 If the percentage of elongation of any tension specimen is less than that specified, and any part of the fracture is more than 3/4 in. from the center of the gauge length as indicated by the gauge marks on the specimen before testing, a retest is allowed. Specimens to be removed from coupons produced per paragraph 7.1.1. 7/1/00

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

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M-201

7.2.5  At the time of purchase, specimens may be cut from castings (excluding flawed specimens) and must have at least 80% of the tensile and yield properties established in paragraph 7.2.2. 7.2.6 Results of testing must show compliance with the requirements of paragraph 7.2.2 prior to shipment of finished castings. 7.3 Impact Test 7.3.1 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. Specimens to be removed from coupons produced per paragraph 7.1.1. A test consists of determining the average energy absorbed from three impact specimens from the same heat. The results shall meet the following minimum requirements at the stated temperatures: Cast Steel

Temperature (°F)

Grades B and B+ Grade C (NT) Grade C (QT) Grade D Grade E

Energy (ft lb)

+20 0  –40  –40  –40

15 15 20 20 20

7.3.2 Impact tests shall be conducted in accordance with the Standard Methods and Definitions  for Mechanical Testing of Steel Products , ASTM Standard A370. 7.3.3 The manufacturer shall test specimens from melt heats and record results, including chemistry of that heat, excluding flawed specimens. Frequency of these te sts shall be one heat per week per grade of steel obtained during the pouring of the last 25% of heat. Specimens to be removed from coupons produced per paragraph 7.1.1. 7.3.4   As a manufacturer’s alternative, impact properties may be determined by use of the Dynamic Tear Test (ASTM E604) or the Nil Ductility Transition Test (ASTM E208). Specimens to be removed from coupons produced per paragraph 7.1.1. 7.3.4.1 The Dynamic Tear Test shall consist of determining the average energy absorbed from three specimens from the same heat, which shall be a minimum of 50 ft lb at the temperatures specified in the table in paragraph 7.3.4.3. 7.3.4.2 The Nil Ductility test shall consist of testing two specimens at the temperatures specified in the table in paragraph 7.3.4.3. Both specimens shall exhibit “no-break” performance. 7.3.4.3 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+ Grade C (NT) Grade C (QT) Grade D Grade E

+60 +60  –60  –60  –60

7.3.4.4 The record keeping requirements and test frequency are the same as specified in paragraph 7.3.3. 7.3.5  A check test may be made by purchaser from a casting at purchaser’s expense. Results of  this testing shall conform to the minimum values specified in paragraph 7.3.4.

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

7.4 Hardness Cast steel components, except as provided for in product specifications, must be within a Brinell Hardness range as follows: Material Grade Identification

BHN Range

Grade A Grades B and B+ Grade C Grade D Grade E

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.

8.0 NUMBER OF TESTS, 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, the physical properties, as required in paragraph 7.0, will be determined from an extra or spare test coupon cast with and attached to som e other casting of the same heat. 9.0 RE-HEAT TREATMENT If the results of the physical test lot do not conform to the requirements specified, the manufacturer may re-heat treat such lot not more than twice, and retests shall be as specified in paragraph 7.0. WORKMANSHIP AND FINISH

10.0 WORKMANSHIP  All castings shall conform to the dimensions on drawings furnished by the purchaser before manufacture is started; or to the dimensions predicated by the pattern supplied by the purchaser, if no drawing has been provided. 11.0 FINISH The castings shall be free from injurious defects and shall be thoroughly cleaned when offered for inspection. 12.0 WELD REPAIR OF DEFECTS 12.1 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. Maximum depth of repaired area must allow at least 1/8 in. 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. Where a defect continues through the casting wall and both sides of the wall are accessible for welding, the casting shall be welded from bot h sides using a double “V” or a “U” contour weld. Where defect continues through the casting and is inaccessible from both sides and unless prohibited by specific component specification, defect may be weld repaired by using a copper backup plate provided the surface is smooth and clean. 12.2 Welders shall be qualified and use procedures under t he welder qualification procedure contained in AWS 15.1, or equivalent, in the position welding is to be performed. 12.3 Defects may be repaired by using a metal-electrode arc welding process that will result in sound weld deposit having, in the heat-treated condition, minimum mechanical properties equal to the requirements for the parent metal. Welding may be performed in either the non-heat-treated or heat-treated condition. Post-weld heat-treatment requirements are outlined in the product specification for the component involved. 7/1/00

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

M-201

12.4 Grade A, B, B+, C, D, or E castings shall not be welded while the temperature of the casting is below 40 °F. Localized preheating is acceptable. If local preheating is performed, the casting shall be uniformly preheated to a temperature between 300 °F and 600 °F, and welding shall be accomplished while the casting is maintained at a temperature above 300 °F. The temperature shall not exceed 600 °F to avoid the possibility of warping. 12.5 For Welding Grade A Steel Castings If shielded metal arc process is used, the electrode shall be E6015, E6016, E6018, or equivalent. 12.6 For Welding Grades B and B+ Steel Castings If shielded metal arc process is used, the electrode shall be a low hydrogen coated type as follows: for Grade B—AWS/ASTM Class E7015, E7016, E7018, E8015, E8016, E8018, or equivalent may be used; for Grade B+—AWS/ASTM E8015, E8016, E8018, or equivalent may be used. 12.7 For Welding Grade C Steel Castings If shielded metal arc process is used, the electrode shall be a low hydrogen coated type,  AWS/ASTM Class E9015, E9016, E9018, or equivalent. At the option of the manufacturer, an electrode of the AWS/ASTM Class E10015, E10016, E10018, or equivalent may be used for higher mechanical properties after heat treatment. 12.8 For Welding Grade D Steel Castings If shielded metal arc process is used, the electrode shall be a low hydrogen coated type AWS/ASTM E11015, E11016, E11018, or equivalent. 12.9 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, E12016, E12018, E13015, E13016, E13018, or equivalent. 13.0 MARKING When marking requirements are not covered by individual product specification, the manufacturer’s identification mark, the pattern number and grade, and, when specified, the purchaser’s initials shall be legibly cast on all castings.  VARIATION IN WEIGHT

14.0 VARIATION IN WEIGHT When not covered by individual product specification, 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. INSPECTION AND REJECTION

15.0 INSPECTION 15.1 The inspector representing the purchaser shall have free entry, at all times while the work on the contract of the purchaser is being performed, to all parts of the manufacturer’s works that concern the manufacture of the material ordered. The manufacturer shall aff ord the inspector, free of charge, all reasonable facilities and necessary assistance to satisfy the inspector that the material is being furnished in accordance with these specifications. Tests and inspection shall be made prior to shipment at the place of manufacture unless otherwise specified. 15.2 The purchaser may make tests to govern the acceptance or rejection of the material in purchaser’s laboratory or elsewhere. Such tests shall be made at the expense of the purchaser. 15.3 Rejection Material represented by samples that fail to conform to the requirements of these specifications, or to individual product specification, will be rejected. B–10

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AAR Manual of Standards and Recommended Practices Couplers and Freight Car Draft Components

15.4 Material that, subsequent to test and inspection at the foundry or elsewhere and its acceptance, shows injurious defects will be rejected, and the manufacturer shall be notified. 15.5 AAR Representation In addition to the purchaser’s representation, an AAR official representative shall have free entry at all times to all parts of the manufacturer’s works that concern the manufacture, test, and inspection of materials for use in Interchange Service. This access is for the purpose of providing assurance that industry standards are being maintained. The manufacturer shall afford the AAR representative all reasonable facilities to ensure that materials are being furnished in accordance with these specifications.

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