Hardening. This is the process of heating to a temperature above the critical range, and cooling rapidly enough through the critical range to appreciably harden the steel.
淬火。这个工艺是把材料加热到临界温度范围之上，然后迅速冷却到临界温度范围以下，使钢材明显变硬。
2
An overall chromium coating improves the corrosion resistance of the generally used through-hardening rolling bearing steel.