EH36MOD钢焊接CGHAZ的相变超塑性对提高疲劳寿命的贡献

研究了焊接ＣＧＨＡＺ的相变超塑性变形及其对疲劳寿命的作用。结果发现：（１）采用相同焊接循环与不同的拘束位移，所模拟的焊接ＣＧＨＡＺ中存在着相变超塑性现象。（２）该超塑性应变为１％时，其疲劳寿命要比无相变超塑性的提高１９％。（３）在无相变超塑性ＣＧＨＡＺ中，（Ｍ－Ａ）组元的形态基本上呈长条状；当相变超塑性应变增至１．０％时，（Ｍ－Ａ）组元变化成长条状与块状的混合型形态。

TRANSFORMATION SUPERPLASTICITY IN WELDING CGHAZ FOR EH36MOD STEEL AND ITS CONTRIBUTION TO INCREASING FATIGUE LIFE

The transformation superplasticity in welding CGHAZ(Course Grain Heat-AffectedZone)and its contribution to increasing fatigue life have been studied.Main results obtainedare as follows:(1)Transformation superplasticity strains are developed in the simulated CG-HAZ by using same thermal cycle with different restrained displacement.(2)Low cvcle fa-tigue life of the CGHAZ is raised by 19%with increasing the superplasticity strains from 0%(no transformation superplasticity)to 1%,(3)In the case of 0%strain,the(M-A)con-stituent morphology is almost of strip form;in the case of 1%strain,the(M-A)morphologyis of mixed form with striped and massive.