AMS 6303 is a specification of Steel 17-22A, which is ultra-high-strength low alloy steel with a high percentage of Carbon, Molybdenum, Vanadium, and Chromium. Its main characteristics are excellent high-temperature strength and high heat resistance.
It is used for manufacturing of shafts, studs and fasteners, mechanical parts in aviation and engines, steam turbines, industrial furnaces, guided missiles, turbine rotors, and petrochemical engineering applications.
The AMS 6303 specification is available as a bar and forging and is characterized by excellent machinability and toughness, and 1000-hour rupture strength of temperatures up to 1100°F (593°C) or 30,000 psi.
Recommended heat treatment for AMS 6303 starts with normalizing at a temperature of 1700-1850°F (926-1010°C) and holding for one hour for each inch of thickness. Then the part should be air cooled or fan cooled if the process is to be accelerated. Please note that all surfaces of the part must have access to air for even cooling.
After normalizing, annealing is done at 1450°F (787°C) for one hour per inch of thickness to get to 1100°F (593°C). Additional hardening can be achieved by oil quenching at a temperature of 1750°F (955°C).
The AMS 6303 specification can be welded using all popular welding processes. The use of a welding rod with the 17-22A(S) is recommended, due to its higher concentration of carbon and chromium.