固溶氮原子对不锈钢单轴及多轴低周疲劳特性的影响

对３１６Ｌ和３１６ＬＮ不锈钢进行了单轴拉压及多轴非比例加载低周疲劳实验研究，分析了固溶的氮原子对单轴及多轴非比例加载低周疲劳特性及其微结构的影响。结果表明，固溶的氮原子增大了不锈钢铁的单轴循环软化程度及非比例循环附加强化程度，延长了不锈钢的单轴拉压低周疲劳寿命，但却缩短了不锈钢的多轴非比例加载低周疲劳寿命，固溶的氮原子对单轴及多轴低周疲劳密度位错结构的形成具有明显的抑制作用，利用Ｍｏｅｓｓｂａｕｅ

THE EFFECT OF NITROGEN ATOMS ON THE CHARACTERISTIC OF LOW CYCLE FATIGUE OF STAINLESS STEELS UNDER UNIAXIAL AND MULTIAXIAL LOADING

The tests on low--cycle fatigue of 316L and 316LN stainless steels under uniaxial tension- compression and multiaxial nonproportional loading are made. The effect of solution nitrogen atoms on the characteristics and microstructures of low-cycle fatigue under tension-compression and multiaxial nonproportional loading is analyzed. The results show that the solution nitrogen atoms increase the degree of uniaxial cyclic softening and multiaxial nonproportional cyclic additional hardening, prolong the uniaxial tension-compression low-cycle fatigue life, however, shorten the low-cycle fatigue life of stainless steels under multiaxial nonproportional loading, and inhibit the formation of the high density dislocation structures in stainless steels under uniaxial and multiaxial low--cycle fatigue. The hypothesis of IS complexes which has not been proved so far is proved indirectly with the methods of Mossbauer spectra.