Stainless Steel Tube Tempering Temperature Purposes

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:

` 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 retained austenite;
a Tempering temperature should be uniform, it is recommended that the best in the salt furnace;
b Stainless steel tube after each tempering must be cooled to room temperature, in order to carry out the next tempering;
c 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.

Annealing measurement requirements
1, Stainless steel pipe annealing measurement can reach the rules measure.
2, Stainless steel tube annealing atmosphere.
3, Cover the gas pressure. Bright out of the furnace should be open, and the external atmosphere cut off; the use of heavy hydrogen for the cover of the gas, as long as the exhaust is through (for extinguishing the discharge of heavy hydrogen). The scope of the furnace material can be reviewed whether the boring, the first furnace, the furnace material must be dried; into the furnace stainless steel pipe can be too much residual water stains, especially if the tube below the hole, then, of course, do not water out, put the stove atmosphere all destroyed.
4, The furnace seal. You can also go through the retreat of the furnace inspection hole inspection, annealing area of the stainless steel tube should be white hot form, but did not show hardening sagging.
5, The furnace water vapor. In order to prevent the emergence of micro-leakage, the furnace cover gas should maintain a positive pressure, if it is heavy hydrogen shielding gas, the normal request 20kBar above. Stainless steel heat solution is normal to take the solution heat solution, that is, everyone called "annealing", the measurement range of 1040 ~ 1120  (Oman specification). Normal use of pure hydrogen as the annealing atmosphere, the atmosphere purity is best above 99.99%, if the atmosphere is another in the case of inert gas, then the purity can be low and a half, but relative to not contain too much oxygen, water vapor. The way to review can be used to tow the towel water in the back of the joints of the joints to see whether the run; inside the most simple run the center of the furnace is back to the center of the tube and out of the central tube, a central gasket is particularly simple wear, to always check often change.