焊接对X65钢腐蚀疲劳裂纹扩展影响的试验研究  

Experimental Study of Effect of Welding on Corrosion Fatigue Crack Propagation of X65 Steel

作　　者：谭玉娜 余建星[1,2,3] 王昭宇 王华昆 陈佰川[1,2] 袁祺伟 TAN Yunau;YU Jianxingi;WANG Zhaoyu;WANG Huakun;CHEN Baichuan;YUAN Qiwei(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China;Collaborative Innovation Center for Advanced Ship and Deep-sea Exploration,Shanghai 200240,China;School of Mechanical and Ship Marine Engineering,Qinzhou College,Qinzhou 535011,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072 [2]高新船舶与深海开发装备协同创新中心,上海200240 [3]钦州学院机械与船舶海洋工程学院,广西钦州535011

出　　处：《热加工工艺》2021年第7期18-22,26,共6页Hot Working Technology

基　　金：国家自然科学基金面上项目资助项目(51879189);国家科技重大专项资助项目(2016ZX05028005-004);广西科技重大专项资助项目(桂科AA17292007)。

摘　　要：对于深海油气输送结构,焊接产生的初始预应力会对其腐蚀疲劳性能产生影响。针对深海油气输送常用材料X65钢开展腐蚀疲劳裂纹扩展试验。分别从焊接热影响区和母材上制备了标准紧凑拉伸(CT)试样,利用直流电压降(DCPD)方法测量了疲劳裂纹扩展长度,对焊接试件的腐蚀疲劳性能进行了研究,并拟合出了两种试件在不同试验环境下的Paris常数C和m。试验结果表明:在0.2 Hz的加载频率下,腐蚀溶液可明显加快裂纹扩展速率,并使裂纹扩展阈值分别提高16.25%和13.75%。焊接试件在空气环境下拟合的C值和m值均要略高于母材试件,在腐蚀环境下其C值和m值要略低于母材试件。For deep-sea oil and gas transport structures, the initial pre-stress generated by welding will affect the corrosion fatigue performance. The corrosion fatigue crack propagation test was carried out on X65 steel which is commonly used for deep-sea oil and gas transportation. The standard compact tensile(CT) specimens were prepared from welding heat affect zone and base material, respectively. Direct current potential drop(DCPD) method was used to measure the fatigue crack length,the corrosion fatigue properties of welding specimens was studied, and the Paris constants C and m of two kinds of specimens were fitted in different test environments. The test results show that the corrosion solution can significantly accelerate the crack growth rate and increase the crack growth threshold by 16.25% and 13.75% respectively at the loading frequency of 0.2 Hz. The C and m values of the welding specimen fitted in the air environment are slightly higher than that of the base metal specimen. The value of the welding specimen in the corrosive environment is slightly lower than that of the base metal specimen.

关 键 词：焊接 X65钢 腐蚀疲劳 裂纹扩展 

分 类 号：TG174.3[金属学及工艺—金属表面处理] TG405[金属学及工艺—金属学]