固溶处理对Mn-N型双相不锈钢堆焊层耐点蚀性能的影响

固溶处理对Mn-N型双相不锈钢堆焊层耐点蚀性能的影响 Effect of solution treatment on pitting corrosion resistance of Mn-N duplex stainless steel surfacing layer 谢秉錡 XIE Bingqi 1 first-author 包晔峰 Bao Yefeng 1 2 3 corresp Baoyf@hhuc.edu.cn 许伟康 XUE Weikang 1 王子睿 WANG Zirui 1 郭林坡 GUO Linpo 1 河海大学机电工程学院 河海大学机电工程学院 College of Mechanical & Electronic Engineering,Hohai University College of Mechanical & Electronic Engineering,Hohai University 河海大学疏浚技术教育部工程研究中心 河海大学疏浚技术教育部工程研究中心 Engineering Research Center of Dredging Technology of Ministry of Education, Hohai University Engineering Research Center of Dredging Technology of Ministry of Education, Hohai University 南通河海大学海洋与近海工程研究院 南通河海大学海洋与近海工程研究院 Institute of Marine and Offshore Engineering, Nantong Hohai University Institute of Marine and Offshore Engineering, Nantong Hohai University 为改善钢铁材料的耐点蚀性能,采用等离子堆焊在Q235钢板上制备Mn-N型双相不锈钢堆焊层。分别采用卧式显微镜和配备EDS的扫描电镜,观测经不同温度固溶处理后堆焊层的显微组织,分析各元素在两相中的分布;采用Fe Cl3溶液对堆焊层进行点蚀浸泡试验,并测量堆焊层在3.5 wt.%Na Cl溶液下的电化学交流阻抗谱(EIS),研究固溶处理温度对Mn-N型双相不锈钢等离子堆焊层的耐点蚀性能的影响。结果表明:随着双相不锈钢堆焊层固溶处理温度的升高,其显微组织中铁素体的耐点蚀性能下降,而奥氏体的耐点蚀性能上升,堆焊层整体的耐点蚀性能呈现先上升后下降的趋势;经1 230℃固溶处理后,堆焊层点蚀速率最低,为0.017 6 g/h;同时,电化学阻抗谱显示,经1 230℃固溶处理后,堆焊层具有最高的耐点蚀性能。固溶处理使合金元素在两相中重新分布,是造成不同温度固溶处理后堆焊层的耐点蚀性能产生差异的主要原因。 In order to improve the pitting corrosion resis tance of steel, a surfacing layer of Mn-N duplex stainless steel was prepared on Q235 steel plate by plasma build-up welding.The horizontal microscope was used to observe the microstructures of the solution-treated surfacing layer, and the distribution of each alloy element was analyzed by scanning electron microscope equipped with EDS. The pitting corrosion resistance of Mn-N duplex stainless steel plasma surfacing layer after treated at different solution temperatures was measured by ferric chloride immersion experiment and Electrochemical Impedance Spectroscopy（EIS）. The results show that, with the increase of the solution temperature, the pitting corrosion resistance of ferrite decreases, while the pitting corrosion resistance of ferrite austenite increases and the pitting corrosion resistance of the surfacing layer shows a trend of increasing in advance and then decreasing.After treated at 1 230 ℃, the surfacing layer has the lowest pitting corrosion rate of 0.017 6 g/h. EIS test shows that the surfacing layer after solution treatment at 1 230 ℃ has the highest resistance to pitting corrosion. The alloy elements redistributed in the two phases during the solution treatment may be the dominant factor for the differences in the pitting corrosion resistance of the surfacing layer after treated at different solution temperatures. 固溶处理 双相不锈钢 等离子堆焊 点蚀 solution treatment Mn-N duplex stainless steel plasma build-up welding pitting corrosion resistance TG455;TG156.94 国家自然科学基金资助（51879089）;中央高校基本科研业务费专项资金资助（B200204036） 2022-03-08 9 51