work hardening index

例句：

1. 1.The work hardening index of the material is 0.35.
   材料的硬度指数为0.35。
2. 2.The hardening index of steel is a measure of its resistance to wear and tear.
   钢的硬化指数是衡量其抗磨损能力的一个指标。
3. 3.The work hardening index can be used to predict the fatigue life of the material.
   工作硬化指数可以用来预测材料的使用寿命。