摘要
采用应变疲劳过程中对试样进行中途回火的方法，研究了回火对疲劳损伤的恢复作用。实验结果发现，中途回火可使疲劳寿命延长。应变量越大，回火的作用越显著；循环寿命分数增加，回火的作用减少。ＴＥＭ观察表明，中途回火使位错密度及位错排列发生变化，从而使疲劳损伤在不同程度上恢复。疲劳断口ＳＥＭ观察发现，中途回火后，应变疲劳断口上的韧性断裂特征比未回火试样明显。
This paper deals with the effect of tempered on fatigue damage by tempering the strain fatigue specimen after cyclic strained up to different life fraction, It is found that the fatigue life increases with the cyclic life fraction.The observation of fatigue substructure by TEM indicates that the density of dislocation and the dislocation structure changes by intermediate tempering,which cause the recovery of partial fatigue damage.The observation of fatigue fractographs by SEM indicates that the feature of toughness fracture in tempered specimen is more evident than the one not tempered.It indicates that the fatigue fracture mechanics changes by intermediate tempering.
基金
国家自然科学基金
