Stainless steel 304 is a Japanese brand, equivalent to 00Cr19Ni10 in China. It belongs to austenitic stainless steel.
The stress relief treatment of austenitic stainless steel is a heat treatment process to eliminate the residual stress of steel after cold working or welding. It is generally heated to 300 ~ 350 ℃ for tempering.
For steels without stabilizing elements Ti and Nb, the heating temperature shall not exceed 450 ℃, so as not to precipitate chromium carbides and cause intergranular corrosion.
For the cold worked and welded parts of ultra-low carbon and alloy Ti and Nb stainless steel, it is necessary to heat at 500 ~ 950 ℃ and then cool slowly to eliminate the stress (the upper limit temperature is taken for the elimination of welding stress), which can reduce the tendency of intergranular corrosion and improve the stress corrosion resistance of the steel.
Therefore, if you want to de stress 304, the reasonable temperature is between 300 ~ 350 ℃, generally 1.5 ~ 2.5 hours / 100mm effective section.
Your question is to remove the stress after bending. Why do you want to remove the stress after bending?
I don’t think so.
If you bend it, you can straighten it without stress relief, because the deformation of austenitic stainless steel will not lead to structural changes, and there is no stress!