Tempering of Stainless Steel Tube

The purpose of tempering stainless steel pipe is to transform the quenched martensite into tempered martensite, eliminate the residual austenite, reduce and eliminate the internal stress, obtain high hardness, wear resistance and red hardness, etc., so as to stabilize the size and improve the mechanical properties, and meet their work requirements. The normal tempering temperature is 540-570 ° C, and the temperature is kept for 1-1.5H in 100% KNC) 3 salt bath. Due to the high-speed tempering of steel, the martensite precipitates and disperses in small w, Mo and V carbides, and the residual austenite is in the process of grade III tempering martensite, so the phenomenon of "secondary hardening" occurs, and triple tempering shall be carried out.



In order to ensure the tempering effect of high speed steel, the following problems should be paid attention to:



① The stainless steel pipe should be quenched immediately after tempering treatment, otherwise, the retained austenite will be stabilized, which is not conducive to the elimination of retained austenite.


② The tempering temperature should be uniform, and it is recommended to put it in the salt furnace.


③ After each tempering, the stainless steel pipe must be cooled to room temperature for the next tempering.


④ The stainless steel pipe at the end of the tool shall be cleaned after cooling to room temperature, otherwise it is easy to cause cracking of the stainless steel pipe.


High temperature stainless steel pipe dry use, do not exceed the limit temperature of high temperature stainless steel pipe, the problem of high temperature stainless steel pipe dry use will not be very big, but this will greatly shorten the service life of high temperature stainless steel pipe, if you use coolant in the center of high temperature stainless steel pipe, it will increase the service life of high temperature stainless steel pipe, so you can know to ensure high temperature stainless steel pipe The service life and performance of the pipe, high temperature stainless steel pipe better not dry use.