H13钢热疲劳性能研究

以盐浴法为手段,对H13钢进行了热疲劳实验,探讨了淬火温度、回火温度、表面处理对其热疲劳失效裂纹的影响并确定了合理的热处理工艺。实验得出:试样热疲劳循环次数在400个周期时,裂纹形成后扩展迅速,裂纹平均生长速度约为2.51×10-3mm/周,而采用1 020℃淬火、640℃回火热处理工艺,与裂纹平均生长速度相比,热疲劳裂纹生长速度减缓了0.45×10-3mm/周,表面渗氮的试样裂纹源可推迟50个热疲劳循环周期。

Thermal fatigue property of die steel H13

A thermal fatigue experiment for die steel H13 was conducted by using salt bath process to explore the effects of quenching temperature,drawback temperature and surface treatment on the failure cracking of thermal fatigue.Then a feasible heat treatment process was determined.It is concluded that the crack grows rapidly after formation when it is at 400 cycle times of thermal fatigue,and the average rate of crack growth is about 2.51×10-3 mm/cycle.The adoption of heat treatment process at 1 020 ℃ quenching temperature and 640 ℃ drawback temperature can make the rate of thermal fatigue crack growth 0.45×10-3 mm/cycle slower than the average rate of crack growth,and the appearance of crack initiation in a test sample with nitriding treatment on surface will be deferred 50 thermal fatigue cycle times.