组织配分对2002双相不锈钢点蚀萌生及扩展的影响  

Effect of Microstructure Distribution on Pitting Initiation and Propagation of 2002 Duplex Stainless Steel

作　　者：雷哲缘 汪毅聪 胡骞[1] 黄峰[1] 刘静[1] LEI Zheyuan;WANG Yicong;HU Qian;HUANG Feng;LIU Jing(Hubei Engineering Technology Research Center of Materials and Service Safety,State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学,省部共建耐火材料与冶金国家重点实验室,湖北省海洋工程材料及,服役安全工程技术研究中心,430081

出　　处：《中国腐蚀与防护学报》2021年第6期837-842,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51871171)。

摘　　要：通过固溶处理得到含有不同占比和元素含量组成相的2002双相不锈钢试样,采用恒电位极化、动电位扫描和表面形貌分析,研究并探讨了组织配分对点蚀萌生及扩展规律及机理的影响。结果表明,随着固溶温度升高,主要合金元素向γ相聚集,α相含量增加,但耐蚀性下降,点蚀更倾向于在弱相α相上萌生,2002双相不锈钢整体点蚀抗性降低。点蚀发生时具有蕾丝花边形貌,蕾丝盖下的点蚀坑具有浅而宽的碟形特征。2002双相不锈钢点蚀抗性越好,点蚀坑越容易沿宽度方向扩展,对深度方向的扩展影响不大。Test pieces of 2002 duplex stainless steel composed of different proportion of phases with various amount of alloying elements were prepared by solution treatment. The effect of microstructure partition on the pitting initiation and propagation of the steel in 3.5%(mass fraction) NaCl solution were investigated by means of potentiostatic polarization, potentiodynamic scanning and surface morphology analysis. Results show that with the increase of solution treatment temperature, the main alloying elements gather to γ phase, the volume faction of α phase increases but the anti-corrosion property of the steel decreases, therewith, pitting initiates on α phase more easily. As a consequence, the pitting resistance of 2002 DSS decreases. The formed pits present lacework-like morphology, beneath the cover of a lacework there is a dish-lie pit with larger mouth opening but shallower depth. In a word, 2002 duplex stainless steel exhibits better corrosion resistance, which may be ascribed to that the formed pits on the steel surface tend preferentially to grow laterally but not deeply.

关 键 词：双相不锈钢 组织配分 点蚀萌生 点蚀扩展 

分 类 号：TG172[金属学及工艺—金属表面处理]