ZG00Cr25Ni7Mo2N海水管路裂纹失效分析  

Failure Analysis of ZG00Cr25Ni7Mo2N Seawater Pipeline Crack

作　　者：禹文娟 李毛毛 盛楠 王潇岚 牛建民 姜风春 YU Wen-juan;LI Mao-mao;SHENG Nan;WANG Xiao-lan;NIU Jian-min;JIANG Feng-chun(Harbin Engineering University,Harbin 150006,Heilongjiang,China;Shanghai Shipbuilding Technology Research Institute,Shanghai 200032,China;Yantai Research Institute and Graduate School of Harbin Engineering University,Yantai 264000,Shandong,China)

机构地区：[1]哈尔滨工程大学,黑龙江哈尔滨150006 [2]上海船舶工艺研究所,上海200032 [3]哈尔滨工程大学烟台研究生院,山东烟台264000

出　　处：《铸造》2025年第1期108-114,共7页Foundry

基　　金：中国博士后科学基金资助项目(2023M732172、2024T171176)。

摘　　要：双相不锈钢(ZG00Cr25Ni7Mo2N)海水管路使用半年后,在管路出水口靠近法兰的位置处出现裂纹。通过宏观形貌检查、微观组织分析、力学性能测试、电偶腐蚀有限元数值模拟等方法,对海水管路开裂原因进行了分析。结果表明:失效管路内部存在明显铸造缺陷,缩松、缩孔等缺陷,可以作为裂纹源引起管道开裂。管路裂纹附近组织成分与基体基本一致,均由三种相(铁素体δ、奥氏体γ、σ相)组成。裂纹对基体的相组成没有明显影响,但裂纹部位铁素体δ体积分数下降,脆性σ相增加,从而导致了材料的性能恶化,使得管路夏比冲击吸收功仅为设计标准下限的4.6%,平均断后伸长率和断面收缩率分别仅为设计标准的44%和13.2%。根据电偶腐蚀有限元数值模拟结果,失效管路的电偶腐蚀问题可能会对其裂纹扩展产生一定影响,但不是裂纹形成的主要原因。Duplex stainless steel(ZG00Cr25Ni7Mo2N)seawater pipeline cracks appeared at the position near the flange after half a year of use.By means of macroscopic morphology inspection,microstructure analysis,mechanical property test and finite element numerical simulation of galvanic corrosion,the cracking causes of seawater pipeline were analyzed.The results show that there are obvious casting defects inside the failed pipeline,and the defects such as shrinkage porosity and cavity can be as crack sources to cause pipe cracking.The structure composition near the pipeline crack is basically the same as that of the matrix,which is composed of three phases(ferrite,austenite,phase).The cracks have no obvious effect on the phase composition of the matrix,but the ferrite δ volume fractions at the crack sites decrease,while the brittleσphase increases,which leads to the deterioration of the material's performance,and the charpy-impact absorption energy of the pipeline is only 4.6% of the design standard lower limit.The average post-fracture elongation and section shrinkage are only 44% and 13.2% of the design standard,respectively.According to the finite element numerical simulation result of galvanic corrosion,the galvanic corrosion may affect the crack propagation,but it is not main cause of the crack formation.

关 键 词：双相不锈钢 海水管路 裂纹 电偶腐蚀 失效分析 

分 类 号：TG247[金属学及工艺—铸造]