Rachet-Fatigue Behavior of 20g Steel and Weld Materials at Different Temperatures
Both uniaxial tensile test and asymmetric stress cycle test were carried out for 20g steel and weld material of the coke tower at 20,250 and 495℃,respectively.The results show that,the yield strength of the two materials decreases with the increase of temperature,and the yield strength and tensile strength of the weld material are significantly higher than 20g steel.Under asymmetric stress loading at different temperatures,the ratchet behavior will occur in both materials and the cycle times become short with the increase of both average stress and stress amplitude.The faster ratchet strain rate brings about shorter cycle times.At 250°C,both 20g steel and weld material show cyclic hardening characteristics due to dynamic strain aging,and the obvious ratchet behavior only happens at high stress levels and quasi-stable state occurs at low stress levels.
20g steelweld materialratchet behaviorfatigue lifeuniaxial tensile testasymmetric stress cycle test
万方数据
维普
