摘要
探究残余应力状态对304不锈钢管点蚀行为的影响,采用开路电位、动电位极化、交流阻抗谱、Mott-Schottky等方法,研究应力状态及Cl^(-)浓度两种关键因素对冷弯加工后的304不锈钢弯管腐蚀行为的影响,测试弯管不同部位在100、1000 mg/L的Cl^(-)溶液中的点蚀行为及钝化膜特性,分析了应力状态和Cl^(-)浓度对不锈钢点蚀行为的影响规律及对应腐蚀机理。结果表明,冷加工后304不锈钢U弯拉伸面、压缩面的残余应力分别为拉应力和压应力,未变形的直管部分几乎无应力。腐蚀试验表明,当Cl^(-)质量浓度为100 mg/L时,残余应力会增强不锈钢耐Cl^(-)点蚀的能力并降低钝化膜的载流子浓度,拉应力作用效果强于压应力,而无应力处蚀坑深度最大(80.426μm);当Cl^(-)质量浓度为1000 mg/L时,拉应力与压应力均降低不锈钢耐Cl^(-)点蚀的能力,且拉应力处蚀坑深度(117.956μm)为同浓度下最大。
This paper explores the effects of residual stresses on the pitting corrosion of 304 stainless steel pipes.The open circuit potential(OCP),polarization test,electrochemical impedance spectroscopy(EIS),Mott-Schottky and other methods are used to study the effects of stresses and Cl^(-) concentration on the corrosion of cold-bent 304 stainless steel elbows.The pitting corrosion and passive film characteristics of different parts of the elbow in 100 and 1000 mg/L Cl^(-) solution were tested.How the stresses and Cl^(-) concentration affect the pitting corrosion of stainless steel and the corresponding corrosion mechanism were analyzed.The results show that the residual stresses on the U-bend tensile surface and compression surface of 304 stainless steel after cold machining are tensile and compressive stresses respectively,and that there is almost no stress on the undeformed straight pipe.The corrosion test shows that when the Cl^(-) concentration is 100 mg/L,the residual stress will enhance the ability of stainless steel to resist Cl^(-) pitting corrosion and reduce the carrier concentration of the passivation film.The effects of tensile stress are stronger than those of compressive stress and the maximum pit depth is 80.426μm).When the Cl^(-)concentration is 1000 mg/L,both tensile and compressive stresses reduce the ability of stainless steel to resist Cl^(-)pitting corrosion,and the pit size at the tensile stress is the greatest under the same concentration condition(117.956μm).
作者
王亮添
胡文钰
黄国斌
徐创丽
徐浩
WANG Liangtian;HU Wenyu;HUANG Guobin;XU Chuangli;XU Hao(Department of Environmental Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Guangdong Shenling Environmental Systems Co.Ltd.,Foshan,Guangdong 528313,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2022年第11期104-114,共11页
Journal of Xi'an Jiaotong University
基金
陕西省自然科学基础研究计划资助项目(2021JM-012)
教育部基本科研业务费资助项目(xjh012020037)。
关键词
不锈钢
残余应力
氯离子
点蚀
腐蚀机理
stainless steel
residual stress
chloride ions
pitting corrosion
corrosion mechanism
作者简介
王亮添(1980-),男,博士生;通信作者:徐浩,男,副教授,博士生导师。
