摘要
在Q345钢基体上,采用激光熔覆技术制备Fe60-xMn20Ni10Co10Crx(x=10,12.5,15,20,25,30)高爛合金涂层,并研究Ci含量对涂层组织结构和耐蚀性的影响。借助X射线衍射仪和扫描电子显微镜分析高爛合金涂层的组织结构,同时通过显微硬度计和电化学工作站表征涂层的显微硬度和冲蚀磨损量。研究结果表明CrlO涂层仅由BCC相构成,其他涂层由简单的BCC和FCC两种相构成。随着Ci含量的增加,FCC相的含量先增多后减少,微观组织由较大的等轴晶变化到细小的树枝晶,再变化到较大的柱状晶。同时,涂层硬度也呈现先增大后减小,在Cr原子分数为20%时达到最大值(约500HV)o在3.5%NaC 1溶液中的耐蚀性试验表明,CrlO涂层具有最小的腐蚀电流密度,Crl2.5具有最高的腐蚀电位。研究表明,激光熔敷高爛合金涂层620具有最好的综合力学和耐腐蚀性能。
The work aims to investigate the effect of Cr content of the coating on the microstructure and corrosion resistance of Fe60_xMn2oNi10Co10Crx(x=10,12.5,15,20,25,30)high-entropy alloy coatings prepared by laser cladding technique on the Q345 steel substrate.The micro structure of the high-entropy alloy coating was analyzed by X-ray diffractometry and scanning electron microscopy.Meanwhile the microhardness and corrosion of the coating were characterized respectively by microhardness tester and electrochemical workstation.The results show that CrlO coating consists only of BCC phase,and other coatings consist of BCC and FCC phases.With the increase of Cr content,the content of FCC phase first increases and then decreases.The microstructure changes from large equiaxed crystal to fine dendrites,and then changes to larger columnar crystals.At the same time,the hardness of the coatings also increased first and then decreased,reaching a maximum value(-500HV)when the Cr atomic fraction was 20%.Corrosion resistance tests in 3.5%NaCl solution showed that the CrlO coating had the lowest corrosion current density and Crl2.5 had the highest corrosion potential.Therefore,laser cladding high-entropy alloy coating Cr20 has good comprehensive mechanics and corrosion resistance.
作者
刘涛
赵立娟
庄梦雅
纪秀林
LIU Tao;ZHAO Lijuan;ZHUANG Mengya;JI Xiulin(School of Mechanical and Electrical Engineering,Hohai University,Changzhou 213022,China)
出处
《航空制造技术》
2019年第21期59-63,共5页
Aeronautical Manufacturing Technology
基金
国家自然科学基金(51875169)
中央高校基本科研业务费(学生项目)(2018B731X14)
江苏省研究生科研与实践创新计划项(KYCX18_0538)
关键词
高爛合金
激光熔覆
组织结构
腐蚀
涂层
High-entropy alloy
Laser cladding
Microstructure
Corrosion
Coating
