904L stainless steel
is a low-carbon high-alloy austenitic stainless steel material. The steel is developed for use in non-oxidizing solutions such as sulfuric acid and is also suitable for use in neutral chlorine-containing (pitting-prone) environments and in environments susceptible to crevice and stress corrosion cracking.
904L is a single phase austenitic stainless steel with good weldability. Due to its high molybdenum content and the specially designed low-impurity-content consumables, the filler metal, although single-phase austenite, prevents hot cracking during the welding process.
904L complies with the following standards: SS2562, DIN1.4539, ASTM N08904 and NFZ1 NCDU25-20.
This material is easy to thermoforming, but care must be taken to keep the thermoforming temperature between 950-1200 °C. Excessive temperature will reduce the forming ability of the steel, and the forming speed in the heating range will be accelerated.
If the final molding is carried out at a recrystallization temperature of, for example, 900 °C or higher and then rapidly cooled, it is generally not necessary to heat-treat after molding. It is also important to have the thermoformed workpiece as a whole at this temperature. In the case of local heating or local slow cooling of the case, after forming the need for heat treatment.
904L has very good cold forming characteristics. Cold-formed, stamped and combined with other forming methods such as complex deep drawing can be used in product manufacturing.
The degree of cold forming and the final condition of the work piece determine whether the formed work piece needs to be annealed, for example annealing in the case of stress corrosion cracking.
904L is quenched and softened when heated to 1100-1150 °C, followed by accelerated cooling. In order to make the rapid cooling plate, if necessary, to accelerate the cooling water to cool.