The purpose of stainless steel tube tempering
is to convert quench martensite into tempered martensite, eliminate residual austenite
, reduce and eliminate internal stress, get high hardness, wear resistance and red hardness, etc., to stabilize the size and improve mechanics performance, to meet their work needs. The normal tempering temperature of 540 ~ 570 °C, in 100% KNC) 3 salt bath insulation 1 ~ 1.5h, due to high-speed steel tempering martensite precipitation in the dispersion of small W, Mo and V carbide, residual austenite in the III fire process into martensite, so with the "secondary hardening" phenomenon, should be three times the tempering.
In order to ensure the tempering effect of high speed steel, should pay attention to the following questions:
① Stainless steel tube quenching should be immediately after the tempering treatment, otherwise it will stabilize the retained austenite, is not conducive to the elimination of residual austenite.
② Tempering temperature should be uniform, it is recommended that the best in the salt furnace.
③ Stainless steel tube after each tempering must be cooled to room temperature, in order to carry out the next tempering.
④ Stainless steel tube after the end of the tool should be cooled to room temperature to clean, or likely to cause cracking of stainless steel tube.
High temperature stainless steel pipe dry use, do not exceed the limit temperature of high temperature stainless steel pipe, dry use of high temperature stainless steel pipe problem will not be great, but this will greatly shorten the life of high temperature stainless steel pipe, if once The use of high temperature stainless steel tube in the center of the use of cooling liquid, will increase the life of high temperature stainless steel pipe, so you can know in order to ensure high temperature stainless steel pipe life and performance, high temperature stainless steel tube is best not to use dry.