304 stainless steel is widely used to manufacture corrosion-resistant and formable equipment and parts because of its good heat resistance. At present, 304 stainless steel has been widely used in food, chemical industry, atomic energy and other industrial equipment and decoration fields, as well as household items, cabinets, indoor pipes, water heaters, boilers, bathtubs, auto parts, medical devices, building materials, chemistry, food industry, agriculture and ship parts.
Manufacturing technology of sus304 stainless steel;
1, solid solution treatment, the heating temperature of solid solution treatment is generally high, which is between1050-1100℃, and it is appropriately adjusted according to the carbon content. Due to the poor thermal conductivity of 18-8 stainless steel, it is necessary not only to preheat before quenching and heating, but also to keep the temperature for a long time during solution treatment (quenching and heating).
2. Stress relief annealing, in order to eliminate the residual stress after cold working, it is treated at a lower temperature. Generally heated to 250-425℃, usually 300-350℃. For steel without titanium or niobium, it should not exceed 450℃ to avoid chromium carbide precipitation and intergranular corrosion.
3. Stabilization treatment: In order to prevent the intergranular corrosion resistance of Ti-Nb austenitic stainless steel from decreasing due to the decrease of tic and NbC during welding or solution treatment, it is necessary to heat the stainless steel to a certain temperature (the temperature makes chromium carbide completely dissolved in austenite, while TiC and NbC are only partially dissolved), and then slowly cool it.
References:
Baidu encyclopedia -—SUS304