Three ways for intermediate heat treatment of 904L stainless steel

904L stainless steel tube after the intermediate heat treatment process, generally known as adjustment processing, in order to obtain a certain amount of martensite, thereby strengthening the steel, the following three common methods:
(1) in the middle of limitations (the T approach) solution treatment and then heated to (760 ± 15) ℃, insulation 90min, due Cr23C6 carbide precipitation from austenite, reduce 904L austenitic stainless steel tubes carbon and alloying elements, the point rises to 70 ℃, then cooled to room temperature then get martensite + α ferrite and retained austenite, the retained austenite in the subsequent decomposition finish was 510 ℃ aging.
(2) high temperature adjustment and cryogenic treatment method (R approach) after solution, the line first heated to 950 ℃ insulation 90min. Since the rise of the Ms point, cooled to room temperature, to obtain a small amount of martensite; after then by -70 ℃ cold treatment, heat 8h, you can get a certain amount of martensite.
(3) cold deformation method (C approach) solution treatment at room temperature cold deformation, cold deformation martensite formation 904L seamless quantity and the amount of deformation and 904L stainless steel tube components related. Generally the amount of deformation of 15% to 20% will be able to obtain the necessary amount of martensite, excessive deformation martensite hardening will occur, the plastic significantly.

404