hardening curve

例句：

1. 1.The hardening curve of the material is a crucial factor in determining its strength.
   材料硬化曲线是决定其强度的关键因素。
2. 2.The hardening curve of the material is a crucial factor in determining its strength.
   材料硬化曲线是决定其强度的关键因素。
3. 3.The hardening curve of the material is a crucial factor in determining its strength.
   材料硬化曲线是决定其强度的关键因素。