X80钢焊接结构海水腐蚀及温度的影响规律  

Effect of Temperature On Corrosion of Weld Structures for X80 Steel in Artificial Seawater

作　　者：牛寅竹 史艳华[1] 杨众魁 王玲[1] 梁平[1] 崔永 NIU Yinzhu;SHI Yanhua;YANG Zhongkui;WANG Ling;LIANG Ping;CUI Yong(School of Mechanical Engineering,Liaoning Shihua University,Fushun 113001,China;Petrochina Fushun Petrochemical Company,Fushun 113001,China)

机构地区：[1]辽宁石油化工大学机械工程学院,抚顺113001 [2]中国石油抚顺石化公司,抚顺113001

出　　处：《腐蚀科学与防护技术》2019年第5期495-500,共6页Corrosion Science and Protection Technology

基　　金：辽宁省教育厅基础研究项目(L2019023)~~

摘　　要：以X80钢焊接结构为研究对象,采用SEM、EDS及化学分析表征X80钢焊接接头的组织及成分分布,采用电化学法测量焊接接头不同部位在模拟海水环境中的极化曲线和电化学阻抗谱,研究温度对其腐蚀行为的影响规律。结果表明:海水介质中焊接热影响区的腐蚀倾向最大,焊缝较母材具有更好的耐蚀性;温度升高加速物质扩散及放电过程,因阳极去极化而加速腐蚀,但焊缝处因生成的腐蚀产物致密且附着性优于母材与热影响区,表现出更好的耐蚀性。分析认为:焊缝因低C、Mo、Nb等元素导致组织较母材粗大,晶界数量明显减少,又因Ni、Cr、Al耐蚀元素的增多,因而表现出较好的耐蚀性;热影响区组织复杂、活化能较高,具有较大的腐蚀倾向。The effect of temperature on the corrosion behavior of weld structures of X80 steel in artificial seawater was studied via polarization curve measurement, AC impedance spectra measurement, SEM, EDS and chemical analysis. The result shows that the heat affected zone presents the greatest corrosion tendency, while the weld seam has better corrosion resistance than the base material. With the increasing temperature, the diffusion, discharge process and thus the corrosion were accelerated due to the depolarization of the anode. The weld seam shows better corrosion resistance rather than the base material and the heat affected zone as well, which may be ascribed to that the compactness and adhesion of the corrosion products on the weld seam are much better than that on the base material and the heat affected zone. In comparison to the base metal, the weld seam presents coarser grains with less grain boundaries as well as lower content of C, Mo and Nb, while, richer in Ni, Cr and Al, which all are responsible to the better corrosion resistance of the weld seam. On the other hand, the heat affected zone presents a complex microstructure of rather nonuniform distribution with very high activation energy, which then results in great tendency of corrosion.

关 键 词：X80钢 焊接结构 海水腐蚀 温度 

分 类 号：TG172.4[金属学及工艺—金属表面处理]