深海管道钢的腐蚀疲劳裂纹扩展特性试验研究  

Experimental Study on Corrosion Fatigue Crack Propagation Characteristics of Deep Sea Pipeline Steel

作　　者：谭玉娜 余建星[1,2,3] 余杨 王昭宇[1,2] 王华昆 李修波[1,2] TAN Yu-Na;YU Jian-Xing;YU Yang;WANG Zhao-Yu;WANG Hua-Kun;LI Xiu-Bo(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)

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]天津大学天津市港口与海洋工程重点实验室,天津300072 [3]北部湾大学机械与船舶海洋工程学院,广西钦州535011

出　　处：《中国海洋大学学报（自然科学版）》2021年第6期109-115,124,共8页Periodical of Ocean University of China

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

摘　　要：采用侧壁开槽型CT试样,分别在空气和3.5%NaCl溶液中进行腐蚀疲劳裂纹扩展试验,研究海底管道用钢X65在海水腐蚀环境下的腐蚀疲劳裂纹扩展特性。为保证试样既能满足腐蚀疲劳试验机的夹具要求,又可控制裂纹沿直线方向扩展,采用侧壁开槽技术对CT试样进行改进;利用有限元软件ABAQUS,建立三维模型,验证了对于侧壁开槽型CT试样,可以采用ASTM标准推荐的应力强度因子表达式对改进后CT试样开展数值计算。利用YYF-50腐蚀疲劳试验装置开展试验,试验结果表明:和惰性环境相比,腐蚀环境不仅会加速X65钢的裂纹扩展速率,还会降低腐蚀疲劳体系下裂纹扩展的门槛值;在腐蚀体系下存在裂纹扩展的稳定阶段,可采用Paris公式对其腐蚀疲劳裂纹扩展速率进行预测。In order to study the corrosion fatigue crack propagation characteristics of X65 steel used in deep sea submarine pipeline,the side grooved CT specimens were used to conduct corrosion fatigue crack growth tests in air and 3.5%NaCl solution,respectively.The side wall grooving technology was applied to CT specimen so as to ensure that the specimen can not only meet the fixture requirements of the corrosion fatigue testing machine,but also control the crack propagation in a linear form.Besides,the three-dimensional model was established by using the finite element software ABAQUS,the finite element analysis shows that the stress intensity factor(SIF)expression recommended by ASTM standard can be used for the grooved CT specimens.What’s more,the corrosion fatigue test machine YYF-50 was used to carry out the test.The experimental results show that compared with the inert environment,the corrosive environment not only accelerates the crack growth rate of X65,but also reduces the threshold value of crack growth.There is a steady phase of crack growth in the corrosion system,and Paris formula can be used to predict the corrosion fatigue crack growth rate.

关 键 词：X65钢 侧壁开槽型CT试样 有限元 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]