SAE AMS 6358G pdf download
SAE AMS 6358G pdf download.Steel Sheet, Strip, and Plate 0.50Cr – 0.55Ni – 0.25Mo (0.38 – 0.43C) (SAE 8740).
1.1 Form:
This specification covers an aircraft-quality, low-alloy steel in the form of sheet, strip, and plate.
1.2 Application:
These products have been used typically for heat treated parts requiring through-hardening to minimum tensile strength of 200 ksi (1380 MPa) in section thickness up to 0.375 inch (9.50 mm) and proportionately lower strength in heavier thicknesses, but usage is not limited to such applications.
2. APPLICABLE DOCUMENTS:
The issue of the following documents in effect on the date of the purchase order forms a part of this specification to the extent specified herein. The supplier may work to a subsequent revision of a document unless a specific document issue is specified. When the referenced document has been canceled and no superseding document has been specified, the last published issue of that document shall apply.
2.1 SAE Publications:
Available from SAE, 400 Commonwealth Drive. Warrendale, PA 15096-0001.
AMS 2252 Tolerances, Low Alloy Steel Sheet, Strip, and Plate
MAM 2252 Tolerances, Metric, Low Alloy Steel Sheet. Strip, and Plate
AMS 2259 Chemical Check Analysis Limits, Wrought Low Alloy and Carbon Steels
AMS 2301 Cleanliness, Aircraft Quality Steel, Magnetic Particle Inspection Procedure
MAM 2301 Cleanliness, Aircraft Quality Steel, Magnetic Particle Inspection Procedure Metric (SI) Measurement
AMS 2370 Quality Assurance Sampling and Testing. Carbon and Low Alloy Steel. Wrought Products and Forging Stock
AMS 2807 Identification, Carbon and Low Alloy Steels, Corrosion and Heat Resistant Steels and Alloys. Sheet. Strip, Plate and Aircraft Tubing
3.3 Properties:
The product shall conform to the following requirements: hardness and bend testing shall be performed in accordance with ASTM A 370:
3.3.1 Average Grain Size: Shall be ASTM No. 5 or finer determined in accordance with ASTM E 112 (See 8.3).
3.3.2 Decarburization: Depending upon thickness of the product, decarburization may be measured by a HR3ON hardness step test method, or by the mlcrohardness traverse method. Additionally, the metallographic method shall be used, in part (See 3.3.2.4.1), to inspect product 0.025 to 0.250 inch (0.64 to 6.35 mm) thick, and it may be used to inspect product with thickness 0,375 inch (9.52 mm) and over.
3.3.2.1 In the case of dispute, the microhardness method, conducted in accordance with ASTM E 384, shall govern. The allowance for decarburization shall be (hat which would have been applicable had the step method been used (See 3.3.2.4.1 or 3.3.2.5.1, as applicable.).
3.3.2.2 SpecImens: Shall be full thickness of the product except that specimens from plate
0.250 inch (6.35 mm) and over in nominal thickness may be slices approximately 0.250 inch
(6.35 mm) thick cut parallel to and preserving one original surface of the plate. Recommended
minimum specimen size is 1 x 4 inches (25 x 102 mm). For product 0.025 to 0.250 inch (0.64 to
6.35 mm), a full cross section metallographic sample shall be prepared to inspect for presense of complete decarburization (ferrite).
3.3.2.3 Procedure: Specimens shall be hardened by austenitizing and quenching; preferably, they shall not be tempered but, if tempered, the tempering temperature shall be not higher than 300 °F (149 °C). During heat treatment, specimens shall be protected by suitable atmosphere or medium or by suitable plating to prevent carbunzation or further decarburization.
332.4 Product 0.025 to 0.250 Inch (0.64 to 6.35 mm), Exclusive, in Nominal Thickness: Protective plating, If used to prevent any decarburization during hardening, shall be removed, and a portion of the specimen shall be ground with copious coolant to prevent thermal or mechanical effects to a depth of 0.050 inch (1.27 mm) or one-half thickness, whichever Is less.
3.3.2.4.1 Allowance: The product shall show no layer of complete decarburizatiori (ferrite), determined metallographically at a magnification not exceeding 100X. It shall also be tree from any partial decarburization to the extent that the difference in hardness between the original surface and the surface (depth) generated by grinding as in 3.3.2.4 shall not be greater than two units on the HRA scale, or equivalent (See 8.2). Also, refer to 3.3.2.1.
3.3.2.5 Product 0.250 to 0.375 Inch (6.35 to 9.52 mm). Exclusive, in Nominal Thickness: Specimens shall be ground to remove 0.010 inch (0.25 mm) of metal to create a test reference surface, and a portion of the specimen shall be further ground to a depth of at least one-third the original thickness of the specimen.
