用正电子湮没谱研究40CrNiMo钢腐蚀疲劳氢致开裂的微观机理  

AN INVESTIGATION OF MICROSCOPIC FRACTURE MECHANISM OF CORROSION FATIGUE OF 40CrNiMo STEEL IN 3. 5% NaCl SOLUTION BY POSITRON ANNIHILATION

作　　者：俞方华[1] 郑万辉[1] 郑文龙[2] 苏立民[2] 朱锡英[2] 闵国全[2] 

机构地区：[1]中国科学院上海原子核研究所 [2]机械工业部上海材料研究所

出　　处：《中国腐蚀与防护学报》1993年第2期171-176,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：中国科学院腐蚀科学开放研究实验室资助课题的部份

摘　　要：用正电子湮没寿命谱和低温加热释氢研究了40CrNiMo钢在3.5%NaCl溶液中腐蚀疲劳氢致开裂的微观机理。腐蚀疲劳断裂前,位错与晶界捕获氢量随腐蚀疲劳时间而增加,氢与晶界交互作用导致预裂缝一扩展就沿晶发展,是发生第一阶段开裂的主要原因;而氢与微空洞相互作用导致了第二阶段的快速断裂。Positron annihilation spectroscopy and thermal evolution of hydrogen have been used to study the microscopic fracture mechanism of corrosion fatigue(CF) of the low alloy high strength 40CrNiMo steel in 3.5% NaCl solution. Before CF fracture, the amount of hydrogen entrapped at the grain boundaries (GB) increases with CF time. The interaction between hydrogen and GB results in the pre-cracking initial growth at the first stage of fracture as shown in the da/dN-ΔK curve. The fast cracking fracture at the second stage of fracture is caused by the interaction of hydrogen with microvoids.

关 键 词：40CRNIMO钢 腐蚀疲劳 氢致开裂 

分 类 号：TG172.5[金属学及工艺—金属表面处理]