Effect of tempering temperature on monotonic and low-cycle fatigue properties of a new low-carbon martensitic steel

The relationship between tempering temperature and low cycle fatigue (LCF) is not clear. New low-carbon martensitic steels under different tempering temperatures (320 degrees C, 350 degrees C, 380 degrees C) are tested for tensile mechanical properties, LCF, and microstructure. The results show that the monotone mechanical properties of martensite steels decrease with the increase of tempering temperature. The microstructure shows that the width of the laths increases, the residual austenite is decomposed, and the dislocation density decreases. A damage hysteresis fatigue life prediction model considering tempering temperature is proposed and the fatigue performance is evaluated. The fatigue performance parameters show that the fatigue damage capacity (W-0) decreases and the damage transition index (beta) increased. The established fatigue life model can predict the fatigue life at different tempering temperatures.

Automated summary

The study investigated the relationship between tempering temperature and low cycle fatigue in new low-carbon martensitic steels. It was found that monotone mechanical properties decrease with higher tempering temperatures, accompanied by changes in microstructure. A fatigue life prediction model considering tempering temperature was proposed, indicating a decrease in fatigue damage capacity and an increase in the damage transition index. The established fatigue life model successfully predicts fatigue life at different tempering temperatures.