ALLEGHENY LUDLUM AL 904L Alloy is an austenitic stainless steel designed for middle to high level corrosion resistance. It is produced to low carbon levels for use in the welded condition. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-511. Producer or source: Allegheny Ludlum Corporation.