tempering hardness

例句：

1. 1. The steel was tempered to achieve the desired hardness level.
   钢材经过回火处理以达到所需的硬度水平。
2. 2.The engineer used a special process to increase the tempering hardness of the alloy.
   工程师使用一种特殊工艺来增加合金的回火硬度。
3. 3. The material's tempering hardness is crucial for its performance in this application.
   这种材料在应用中的性能与其回火硬度密切相关。