nitriding layer

例句：

1. 1. The steel was given a nitriding treatment to improve its hardness and wear resistance.
   钢材经过氮化处理以提高硬度和耐磨性。
2. 2. The engineer used a nitriding process to create a smoother surface for the machine parts.
   工程师使用氮化工艺为机器部件创造了更光滑的表面。
3. 3. The nitriding layer on the surface of the tool is essential for its long life and durability.
   工具表面层的氮化层对其长久耐用至关重要。