【摘要】 研究了调质态40Cr钢在循环压应力作用下的疲劳行为。试验得出,即使所施的最大压应力远远超过材料的压缩屈服极限,40Cr光滑试样在循环压缩状态下也不会产生宏观疲劳裂纹,但却能使它在随后的拉一压疲劳中寿命大大降低,表明压应力使材料产生了疲劳损伤。扫描电镜下的显微观察表明,这种疲劳损伤的实质是材料中形成了微裂纹。更多还原

【Abstract】 The fatigue behavior of a high temperature tempered 40 Cr steel under cyclic compressive loading was investigated. No macro crack was found with the cyclic push-push stress applied to the smooth specimens even the maximun compressive stress was much higher than the compressive yield stress of the material.But it turned out that the endurance life of the specimen for push-push fatigue was significantly decreased if the specimen had experinced compression before. Thus,it is suggested that damage are likely to be induced during compressive fatigue, Observation with SEM showed the formation of micro crack in the specimen is associated with the damage of the material.更多还原