Specifications_9310_steel.pdf

Specifications

9310 steel

Compositional and melting requirements

All AISI 9310 (AMS 6265) bars shall come from a single heat, to minimize compositional and microstructural variations. The steel shall be produced from a single master heat using electric arc furnace melting procedures, followed by argon-oxygen decarburization refining (AOD) and then vacuum arc remelting (VAR).

The steel shall meet the compositional requirements of AMS 6265M (see Table below), with the following exceptions. The phosphorus, sulfur, and copper shall have the following maximum limits: P ≤ 0.010, S ≤ 0.010, Cu ≤ 0.20, V ≤ 0.030, Nb ≤ 0.005, and Ti ≤ 0.003 (all in mass %).

No limitations on V, Nb, and Ti are not included in AMS 6265M. These three elements shall be analyzed by an independent laboratory designated by NIST. NIST will have the option to accept or reject the material based on any deviation from the above-mentioned specifications for V, Nb, and Ti.

The composition shall be certified using standard analytical procedures, such as optical emission spectroscopy or x-ray florescence, and the equipment is to be calibrated by standards traceable to

NIST.

Processing requirements

The VAR ingots shall be forged, rolled to billet, conditioned, then hot rolled to bar (if an alternate process has not been mutually proposed.) The bar shall be finished to 0.50" square bar (+0.15", -0.00") and straightened. The corner radius of the finished bars cannot exceed 0.03".

Chemical composition, mass % Min Max

C 0.07 0.13 Si 0.15 0.35

Mn 0.40 0.70 P 0.010 S 0.010 Cr 1.00 1.40 Mo 0.08 0.15 Ni 3.00 3.50 B 0.001 Cu 0.20 Nb 0.005 Ti 0.003 V 0.030

The microstructure shall be uniform through the thickness, with a maximum grain size of ASTM number 7. In other attributes (decarburization, segregation, surface condition, etc.), the steel must be suitable for use as 10 mm square Charpy V-notch specimens.

The 0.50" bar shall be annealed to a maximum hardness of RB-95. The goal here is to produce bars with a minimum of large carbides in the structure, the most uniform carbide precipitation possible, and a uniform hardness. The bar is required to be machine straightened (for twist and bow), and shipped in lengths of no more than 6 feet.