quenching nitrate salt tank

nitrate salt as quenching medium has many advantages compared with quenching oil. only from the comparison between nitrate salt martensitic quenching and ordinary oil quenching:

1, there is no steam film stage in the quenching process of nitrate salt melt, and the cooling speed in high temperature zone is very fast, therefore, excellent quenching structure can be obtained for thick-walled workpieces, and the effective wall thickness of GCr15 steel can reach 35mm, and the metallographic structure is qualified.

2, nitrate salt melt and isothermal cooling rate in the low temperature zone is almost zero, so the quenching deformation is very small.

3, and the cooling speed of nitrate salt can be adjusted by adjusting the water content (between the cooling speed of hot oil and 4 times the oil speed), which is very simple and convenient.

4. The surface of the workpiece is in a compressive stress state, which reduces the tendency of workpiece cracking and can improve the life of the bearing.

5. after quenching, the color of the workpiece is uniform and consistent light blue with metallic luster (that is, the color at the chamfer of imported SKF bearing). after cleaning, the workpiece does not need beam blasting and has good corrosion resistance.

It is the characteristic of this almost ideal cooling medium that makes nitrate quenching one of the important means for SKF, FAG and other world-renowned bearing brands to improve the heat treatment level.