Approved By: Metallurgical Engineer Date: June 1, 2006 Excel Foundry and Machine, Inc.
Excel Material Specifications Manual !!!! """" #### 6 $"
1.0 Material: FG 4340 Medium Carbon Alloy Steel Forging.
2.0 Characteristics: Medium carbon alloy steel which can be oil quenched and tempered to a broad range of
hardness, strength and toughness; or flame or induction hardened when maximum surface hardness is required for better wear resistance. AISI 4340 has the highest hardenability of medium carbon steels. Most frequently used for heavily stressed parts operating under heavy duty conditions. Due to the high carbon content, these steels must be fully stress relieved before machining if they are processed with heat (i.e. torch cutting or welding).
3.0 Scope: Steel for use in rollers, pins, plates, retainers, spacers, or sleeves.
4.0 Specification Numbers: The following table gives a cross reference of specification numbers which describe equivalent materials.
AISI Number UNS Number Excel Number
4340 G43400 FG 4340
5.0 Chemical Composition: The steel shall comply with the chemical composition requirements listed in table 1. 5.1 Heat Analysis: An analysis shall be performed on each heat of material. If possible, the test sample will
be taken at the time of pouring. If this test sample is lost or rendered unusable, chemical compositions may be determined from a sample taken from alternative locations near the surface of the ingot or billet, as required to establish the analysis. If two or more heats are used to pour large ingots, the weighted
average of the chemical analysis of the heats involved will conform to table 1. Table 1: Chemical Composition Limits for FG 4340
Fe C Mn Ni Cr Mo P S Si
Max. Balance 0.43 0.80 2.00 0.90 0.30 0.035 0.040 0.35
Min. - 0.38 0.60 1.65 0.70 0.20 - - 0.15
6.0 Heat Treat Requirements: All forgings shall be heat treated in accordance with the class designation assigned either on print, purchase order, or by agreement with Excel Foundry and Machine and defined in Table 2. Quenching should be accomplished in a manner which avoids quench cracking. Tempering should occur
immediately after quenching. Tempering should be at a temperature which avoids temper embrittlement. Cooling from the temper temperature should be at a rate fast enough to avoid temper embrittlement.
7.0 Mechanical Properties: The forgings shall conform to the mechanical properties listed in table 2. Samples shall be prepared, and testing conducted in accordance with ASTM A370.
7.1 Size Classification: The dimensions of the forging at the time of heat treatment shall be used for size classification. For Solid forgings either the as forged or rough machined diameter or thickness shall be
Approved By: Metallurgical Engineer Date: June 1, 2006 Excel Foundry and Machine, Inc.
Excel Material Specifications Manual !!!! """" %%%% 6 $"
used for size classification. For Ring of Hollow forgings the wall thickness or width (whichever is smaller), shall be used for size classification.
7.2 Number of Tests:
7.2.1 Forgings Under 5000 lb (2270 kg): For forgings heat treated with a rough machined weight of less than 5000 lb (2270 kg) each, one test (longitudinal and tangential where applicable) from each size classification will be tested from each heat and each annealing or normalizing charge, or from each heat in each normalizing or quenching charge represented in each tempering charge.
7.2.2 Forgings Over 5000 lb (2270 kg) but less than 7000 lb (3180 kg): Forgings with a rough machined weight over 5000 lb shall have one test (longitudinal and tangential where applicable) for each forging.
7.2.3 Forgings over 7000 lb (3180 kg): On forgings with a rough machined weight over 7000 lb, two tests (longitudinal and tangential where applicable) shall be taken. These tests shall be 180 ° apart on disk or ring forgings. On shafts and long hollow cylinders (over 80 in (2.0 m)) in length these tests shall be taken 180° apart and from opposite ends of the forging. On Shafts and cylinders less than 80 in (2.0 m) both tests may be located on the same end of the forging, 180° apart.
7.3 Prolongation: A sufficient number of forgings shall have prolongations for extracting mechanical property tests. The location of these prolongations shall conform with figure 1 of ASTM A668. The size of the prolongation shall be determined by the nominal outside rough machined diameter of the forging, disregarding large ends, collars, flanges, and journals. Tension specimens shall be machined from the prolongation in accordance with ASTM A668.
7.4 Brinell Hardness: If Brinell hardness is specified the hardness test shall be taken using a Brinell King Tester employing a 3000 kilogram (kg) load with a 10 millimeter (mm) ball. The hardness test shall be performed after heat treatment on a surface from which scale, or other foreign matter have been removed. It shall be assured that the hardness tests are performed on surfaces which have had all the decarburized metal removed to ensure accurate assessment of the forging’s hardness.
7.4.1 The average hardness reading on each forging shall be within the range specified on the print or on table 2 if not specified on the print. The variation in hardness on any forging exceeding 250 lb (113 kg) shall not exceed 40 HB.
7.4.2 For rings, disks, and hollow forgings over 250 lb at least two hardness measurements shall be taken 180° apart on each flat face. The relative position of hardness readings on opposite faces should be offset 90° (12:00 and 6:00 on one face, 3:00 and 9:00 on the opposite face). 7.4.3 For forgings less than 250 lb (113 kg) the Brinell hardness tests may be made on the broken
test specimens representing the heat or heats in each heat treating charge.
7.4.4 Forgings may be purchased on the basis of hardness alone. In this case the class shall be followed by an H (for example class KH < 7” is normalized, quenched and tempered to 212 to 269 Brinell).
Approved By: Metallurgical Engineer Date: June 1, 2006 Excel Foundry and Machine, Inc.
Excel Material Specifications Manual !!!! """" 6 $"
Table 2: Mechanical Property Requirements
Class Size, in. (mm) Min Tensile
Strength, PSI (MPa) Min Yield Strength, PSI (MPa) Elong ation, % Reduction
of Area, % Hardness Brinell
G or GH(Annealed, or normalized , or normalized and tempered) < 12 (305) 12 (305) - 20 (508) 80,000 (550) 80,000 (550) 50,000 (345) 50,000 (345) 24 22 40 38 163 – 207 163 – 207 H or HH (Normalized and Tempered) 7 (178) – 10 (254) < 7 (178) 10 (254) – 20 (508) 90,000 (620) 90,000 (620) 90,000 (620) 60,000 (415) 58,000 (400) 58,000 (400) 22 21 18 44 42 40 187 – 235 187 – 235 187 - 235 J or JH (Normalized and Tempered, or normalized, quenched and tempered) < 7 (178) 7 (178) – 10 (254) 10 (254) – 20 (508) 95,000 (655) 90,000 (620) 90,000 (620) 70,000 (485) 65,000 (450) 65,000 (450) 20 20 18 50 50 48 197 – 255 187 – 235 207 - 255 K or KH (Normalized,
quenched and tempered) 7 (178) – 10 (254) < 7 (178) 10 (254) – 20 (508) 105,000 (725) 100,000 (690) 100,000 (690) 80,000 (550) 75,000 (515) 75,000 (515) 20 19 18 50 50 48 212 -269 207 – 269 207 - 269 L or LH (Normalized,
quenched and tempered) 4 (102) – 7 (178) < 4 (120) 7 (178) – 10 (254) 10 (254) – 20 (508) 125,000 (860) 115,000 (795) 110,000 (760) 110,000 (760) 105,000 (725) 95,000 (655) 85,000 (585) 85,000 (585) 16 16 16 14 50 45 45 40 255 – 321 235 – 302 223 – 293 223 - 293 M or MH (Normalized,
quenched and tempered) 4 (102) – 7 (178) < 4 (120) 7 (178) – 10 (254) 10 (254) – 20 (508 145,000 (1000) 140,000 (965) 135,000 (930) 135,000 (930) 120,000 (825) 115,000 (790) 110,000 (658) 110,000 (658) 15 14 13 12 45 40 40 38 293-352 285 – 341 269 – 331 269 – 341 N or NH (Normalized,
quenched and tempered) 4 (102) – 7 (178) < 4 (120) 7 (178) – 10 (254) 10 (254) – 20 (508 170,000 (1175) 165,000 (1140) 160,000 (1105) 160,000 (1105) 140,000 (965) 135,000 (930) 130,000 (905) 130,000 (905) 13 12 11 11 40 35 35 35 331 – 401 331 – 401 321 – 388 321 - 402
8.0 Workmanship, Finish and Appearance: The forging shall conform to the finish specified on the drawing or shall otherwise have a good workmanlike appearance.
9.0 Quality/Dimensions: All forgings shall be made in a workmanlike manner and shall conform to the dimensions on the drawings.
Approved By: Metallurgical Engineer Date: June 1, 2006 Excel Foundry and Machine, Inc.
Excel Material Specifications Manual !!!! """" 6 $"
10.0 Additional Inspections: When specified by purchase order or drawing, additional inspections (magnetic particle, X-ray, ultrasonic, dye penetrant, etc.) may be required. If required, ultrasonic testing shall be in accordance with the latest issue of ASTM Practice A 388/A 388M, and Magnetic Particle testing in accordance with ASTM Test Method A 275/A 275 M.
11.0 Weld Repair: Repair welding for forgings is generally not permitted.
12.0 Retreatment: If the mechanical test results do not conform to the specified requirements, the manufacturer may retreat the lot not more than three additional times, and retests shall be made. Retreatment is defined as complete reaustenization. Multiple retempering is not precluded by this requirement.
13.0 Rejection: Any forging with injurious discontinuities (observed either before or after acceptance) shall be subject to rejection.
14.0 Certification Requirements:
14.1 Certificate of Conformance: Required for all forgings purchased.
14.2 Chemical analysis and/or mechanical testing with the appropriate reports may be required by the Quality, Engineering or Purchasing Departments, or by the customer
.
14.2.1 Chemical Analysis Report: If stated as a requirement on the forging order, the Supplier shall furnish a chemical analysis report for each heat of forgings. If no chemical analysis report is required, the Supplier is required to maintain a certificate of analysis at the suppliers facility for a minimum of two years.
14.2.2 Mechanical Properties Report: If stated as a requirement on the forging order, the Supplier shall furnish information regarding the mechanical properties for each heat of forgings. If no mechanical analysis report is required, the Supplier is required to maintain a material test report including mechanical properties for a minimum of two years.
15.0 Forging Identification: When possible, the drawing and/or forging order shall designate the type and location of the marking by the Supplier. Identification marking, as a minimum, shall include:
-Forging part number -Heat and/or serial number
16.0 Ordering Information: The following information, as a minimum, should be included on the forging order: -Part name
-Part number -Quantity required -Delivery schedule
-Title, number and date of this standard
Approved By: Metallurgical Engineer Date: June 1, 2006 Excel Foundry and Machine, Inc.
Excel Material Specifications Manual !!!! """" $$$$ 6 $"
REFERENCE SPECIFICATIONS
ASTM A668/A668M Standard Specification for Steel Forgings, Carbon, and Alloy, for General Use.
ASTM A370 Mechanical Testing of Steel Products
ASTM A388/A388M Practice for Ultrasonic Examination of Heavy Steel Forgings.
ASTM A275/A275M Test Method for Magnetic Particle Examination of Steel Forgings.
ASTM A788 / 788M Standard Specification for Steel Forgings, General Requirements.
Approved By: Metallurgical Engineer Date: June 1, 2006 Excel Foundry and Machine, Inc.
Excel Material Specifications Manual !!!! """" &&&& 6 $"
