剖分试样真空回复热处理法研究氢腐蚀裂纹的愈合  

HYDROGEN-ATTACKED CRACK HEALING WITH RECOVERING HEAT TREATMENT OF DISSECTED-SPECIMEN IN VACUUM ENVIRONMENT

作　　者：徐璟[1] 董超芳[1] 李晓刚[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《中国腐蚀与防护学报》2004年第4期198-202,共5页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金 ( 5 99710 11)及 973项目"材料的环境行为与失效机理"

摘　　要：采用剖分试样真空回复热处理法对低碳钢和Cr-Mo钢的氢腐蚀裂纹愈合机理进行了研究 .结果表明 ,在单纯高温条件下 ,低碳钢和Cr-Mo钢氢蚀裂纹均有所减小 ,尤其以裂纹尖端愈合较为明显 .愈合程度与裂纹尺寸有关 ,小尺度裂纹优先发生闭合 .分析表明 ,氢蚀裂纹愈合的机制主要是热扩散 ,Fe和C在钢中的扩散是内部裂纹自愈合的必要条件 .在Fe和C原子扩散足够快的情况下 ,氢蚀裂纹愈合的条件是塑性变形能Es 大于裂纹愈合所必须克服的表面张力能 .同时 ,相变、应力应变等因素均对其产生重要积极的作用 .The healing mechanism of hydrogen-attacked crack and its influencing factors to the low carbon steel and Cr-Mo steel during the healing process was studied by recovering heat treatment of split specimens in vacuum.The result showed that crack pacing turned much smaller under the condition of pure heating,especially for crack tips.The healing effect was well related to the length of cracks with the shorter in priority.By the primary mechanism of thermal diffusion,iron and carbon atoms must diffuse at the high speed in steel to realize that plasticity deformation energy (E s) exceeds and overcomes surface tensile force energy.In addition,phase transformation and stress-strain relationship also have positive effects on the process.

关 键 词：氢腐蚀 裂纹 愈合 热处理 

分 类 号：TG172.83[金属学及工艺—金属表面处理]