spark discharge hardening

例句：

1. 1. The processof spark discharge hardening is essential for the production of high-quality steel.
   火花放电硬化过程对于生产高质量钢材至关重要。
2. 2.During spark discharge hardening, the material undergoes a rapid transformation that results in its hardness and strength being significantly increased.
   在火花放电硬化过程中，材料经历快速变化，导致其硬度和强度显著增加。
3. 3. In order to achieve optimal spark discharge hardening results, it is important to control the parameters carefully.
   为了获得最佳的火花放电硬化效果，需要仔细控制参数。