hardening bath

例句：

1. 1. To harden the metal, it's heated to a high temperature.
   为了硬化金属，它被加热到高温。
2. 2. The process of hardening is essential for the durability of the material.
   硬化过程对于材料的耐用性至关重要。
3. 3. After hardening, the metal becomes stronger and more resistant to wear.
   硬化后，金属变得更强，更能抵抗磨损。