Cr含量及涂层厚度对超高速激光熔覆马氏体不锈钢涂层组织及耐蚀性能的影响  

Influence of Cr Content and Coating Thickness on the Microstructure and Corrosion Resistance of Ultra-high-speed Laser Cladded Martensitic Stainless Steel Coatings

作　　者：陈田慧 帅若辉 周吉 杨继凯 刘伊 蔡志海 王海斗 徐一斐 娄丽艳[1,2] 李成新 CHEN Tianhui;SHUAI Ruohui;ZHOU Ji;YANG Jikai;LIU Yi;CAI Zhihai;WANG Haidou;XU Yifei;LOU Liyan;LI Chengxin(State Local Joint Engineering Laboratory of Intelligent Manufacturing Technology for Automotive Molds,Tianjin University of Technology and Education,Tianjin 300222,China;Tianjin Key Laboratory of High Performance Precision Molding Manufacturing Technology and Equipment,Tianjin 300222,China;School of Materials Science and Engineering,Xi′an Jiaotong University,Xi′an 710049,China;National Engineering Research Center for Remanufacturing,Army Academy of Armored Forces,Beijing,100072,China;China Machinery Institute of Advanced Materials Co.Ltd.,Zhengzhou 450001,China)

机构地区：[1]天津职业技术师范大学汽车模具智能制造技术国家地方联合工程实验室,天津300222 [2]天津市高性能精准成形制造技术与装备重点实验室,天津300222 [3]西安交通大学材料科学与工程学院,西安710049 [4]陆军装甲兵学院机械产品再制造国家工程研究中心,北京100072 [5]中机新材料研究院(郑州)有限公司,郑州450001

出　　处：《有色金属工程》2024年第12期177-188,共12页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(52130509);天津市自然科学基金资助项目(22JCYBJC01650);天津市教委科研计划项目(2020KJ108)。

摘　　要：采用超高速激光熔覆技术制备了厚度约为850μm和540μm的马氏体不锈钢耐蚀涂层,对比分析了不同Cr含量下不同厚度涂层的微观组织及显微硬度、耐蚀性能。结果表明:马氏体不锈钢涂层硬度均显著高于基体。高Cr涂层马氏体含量更高且在细晶强化及弥散强化的协同作用下,高Cr薄涂层硬度最高可达537.71HV 0.2。高Cr厚涂层由于晶粒细小、Cr含量更高且分布更均匀,电化学测试显示出了更低的腐蚀电流密度、更高的腐蚀电位及最大的容抗弧半径、阻抗值,耐腐蚀性能最优。中性盐雾腐蚀实验结果表明,晶间贫Cr是马氏体不锈钢涂层腐蚀失效的主要原因,但是涂层中Cr含量及成分均匀性增加、涂层厚度增加,将阻碍腐蚀介质的渗透,有利于涂层长期耐蚀性能的提升。Martensitic stainless steel coating of varying thicknesses were deposited by ultra-high-speed laser cladding technology.The microstructure,microhardness,and corrosion resistance of the coating under different Cr contents were analyzed.The results shows that the hardness of martensitic stainless steel coatings are significantly higher than that of the substrate.Coating with high Cr content exhibite increased martensite content.Due to the synergistic effects of martensitic strengthening,fine-grain strengthening,and dispersion strengthening,the thinner coating with higher Cr content achieve the highest hardness,reaching up to 537.71HV 0.2.At the same time,due to the fine grain,higher content and more uniform distribution of Cr element,the thicker coating with higher Cr content exhibite superior corrosion resistance in electrochemical testing,with a lower corrosion current density,higher corrosion potential and the maximum arc radius and impedance values.Neutral salt spray corrosion test results shows that the intergranular Cr deficiency is the main reason of corrosion failure of martensitic stainless steel coatings.However,increasing the Cr content and its uniform distribution,along with increasing the coating thickness,hinder the penetration of corrosive media,thereby enhancing the long-term corrosion resistance of the coating.

关 键 词：涂层 激光熔覆 马氏体不锈钢 微观组织 耐蚀性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]