HUA Jianmin, WANG Fei, XUE Xuanyi, et al. Low-cycle fatigue performance of stainless-clad bimetallic steel bars after exposure to elevated temperatures[J]. 2022, 54(4): 150-160.
HUA Jianmin, WANG Fei, XUE Xuanyi, et al. Low-cycle fatigue performance of stainless-clad bimetallic steel bars after exposure to elevated temperatures[J]. 2022, 54(4): 150-160.DOI: 10.11918/202108049.
In order to evaluate the low-cycle fatigue performance of stainless-clad bimetallic steel bars (SCBSBs) after fire
low-cycle fatigue test was carried out on SCBSB specimens with eight different temperature gradients
and the hysteretic curve and fatigue life of SCBSBs after fire were obtained. Based on the test results
the effects of exposure temperature on the maximum tensile and compressive stress
plastic strain amplitude
and energy density of SCBSBs were analyzed. The variation of the metallographic structure of SCBSBs was observed
and the failure modes were discussed. Results show that when the exposure temperature was higher than 500 ℃
the low-cycle fatigue performance of SCBSBs first decreased and then increased with the increase in the temperature
and the fatigue life and energy density reached the minimum values at 700 ℃. The fatigue strength and plastic strain of SCBSBs decreased and increased respectively after exposure to elevated temperatures. Changes in the metallographic structure resulted in the differences in the low-cycle fatigue performance of SCBSBs after exposure to elevated temperatures. The metallographic structure of carbon steel core bar was changed when the exposure temperature was higher than 700 ℃
and granular pearlite was formed after cooling. The results clarified the low-cycle fatigue failure mechanism of SCBSBs and revealed the evolution trend of low-cycle fatigue performance of SCBSBs after exposure to elevated temperatures.