腐蚀疲劳断裂前氢与缺陷相互作用的正电子湮没研究  

A study of hydrogen-defects interaction in corrosion fatigue process by positron annihilation

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

机构地区：[1]中国科学院上海原子核研究所,上海201800 [2]上海材料研究所,上海200433

出　　处：《核技术》1993年第3期134-139,共6页Nuclear Techniques

基　　金：中国科学院腐蚀科学开放研究实验室资助课题

摘　　要：用正电子湮没谱和加热释氢研究了低合金高强钢人工海水腐蚀疲劳断裂前经若干小时疲劳的样品。实验结果表明,腐蚀疲劳早期阶段产生的位错、空位团以及钢中晶界是氢的捕获位,其捕获氢量随疲劳时间增加。氢与空位相互作用使空位团尺寸增加,数目增多,氢与位错相互作用促使位错增殖且随疲劳时间增加。晶界与氢相互作用能随疲劳时间、晶界捕获氢量增加而降低。碳化物沿晶析出促进了晶界捕获氢。较低的晶界-氢结合能有利于氢沿晶运动,促使预裂缝沿晶发展。Positron annihilation spectroscopy and thermal release of hydrogen have been employed to study the 40CrNiMo high strength steel in seawater corrosion fatigue process before fracture. It was found that dislocations, vacancy clusters or microvoids and grain boundaries were the trapping seats for hydrogen, the amount of hydrogen trapped by these defects increased with corrosion fatigue duration. Dislocation multiplication and the increase of number and size of vacancy clusters or microvoids due to interaction between hydrogen and defects were observed. In addition, interaction energy between hydrogen and both dislocation and grain boundary, especialy the latter, decreased with corrosion fatigue duration, which may be favourable to promote hydrogen movement and the pre- cracking fracture along grain boundaries.

关 键 词：正电子湮没 氢 缺陷 腐蚀疲劳 

分 类 号：TG115.25[金属学及工艺—物理冶金]