循环载荷作用下X70管线钢在近中性溶液中应力腐蚀裂纹的扩展行为  

SCC Propagation Behaviour of X70 Pipeline Steel under Cyclic Loading in Near-neutral Solution

作　　者：郭浩[1] 刘玉高[1] 李光福[2] 杨武[2] 

机构地区：[1]青岛农业大学机电工程学院,山东青岛266109 [2]上海材料研究所,上海200437

出　　处：《机械工程材料》2009年第4期39-42,共4页Materials For Mechanical Engineering

基　　金：国家重点基础研究专项经费资助项目(G19990650);青岛农业大学博士启动基金资助项目(630509)

摘　　要：研究了在循环载荷作用下V形和线形缺口X70管线钢试样在近中性溶液中的应力腐蚀裂纹的扩展行为。结果表明:线形缺口比V形缺口更容易使裂纹扩展,其原因是线形缺口试样的应力集中系数大于V形缺口试样的,且裂纹扩展速度随应力比的降低而增加;在裂纹扩展初期,环境是主要的影响因素,随着裂纹扩展的不断进行,力学作用逐渐增强,当应力强度因子幅ΔK达到某一值时,裂纹由稳定扩展转变为不稳定的快速扩展。SCC propagation behavior of X70 pipeline steel specimens with V-shape and linear shape notches under cyclic loading in near-neutral solution was studied. The results show that linear shape notch made the cracks propagate easier than V-shape notch because the stress concentration factor of linear shape notch specimen was larger than that of V-shape notch specimen. And the crack propagation rate increased with the decrease of stress ratio. The environment was dominant affecting foctor of crack propagation at the beginning, and the mechanical role was enhanced gradually with the continuous propagation of reached a certain value, the propagation of cracks transferred cracks. When stress intensity factor amplitude △K from a stable stage to an unstable quick period.

关 键 词：X70管线钢 循环载荷 缺口 应力集中系数 裂纹扩展 

分 类 号：TG172.8[金属学及工艺—金属表面处理]