Martempering

Hardening process where the workpiece is held in a molten salt bath just above the martensite start temperature to equalize internal temperatures and minimize distortion.

You do warm bath hardening to keep the temperature difference between the surface and the core small. This minimizes distortion and the workpiece gets more uniform mechanical properties. The part is held in a salt bath until the temperature is equalized over the entire cross-section. If you don't hit the temperature or holding time accurately, the hardness will be uneven or the part can even crack. Then you cool normally to stabilize the structure.

MetallurgieSchweißtechnik