【摘要】 应用显微硬度计测定了低周疲劳中正火45~#钢光滑试样的表面维氏显微硬度变化规律.随循环进行,硬度均值呈现初期减小、逐渐增大及后期再次减小3个阶段.硬度方差在整个寿命域内呈现出较大离散特征.通过对显微压痕的弹塑性分析,初步研究了疲劳过程中材料表观塑性状态变化和硬化与软化特性.更多还原

【Abstract】 The experimental rule of Vickers microhardness on the surface of normalized 45~# steel in a smooth sample was measured with microhardness tester during low cycle fatigue.It showed that the statisti- cal means of microhardness appeared three periods with the number of cycle,i,e.decreasing during initial stage,increasing gradually and decreasing again during later stage,and the mean square deviations of micro- hardness appeared larger scatter within the fatigue life.By analyzing the microindentation with elastic-plastic method,the changes of the cyclic plastic state and the properties of the hardening and softening of the materi- al on the surface of specimens during fatigue were studied.更多还原