摘要
KMN钢是大型离心式压缩机叶轮常用材料,服役过程中常出现磨损、腐蚀等损伤导致失效,激光熔覆技术是实现损伤叶轮修复再制造的有效手段。使用Fe Cr合金粉料通过激光熔覆技术在预置缺陷的KMN钢基体上制得修复层。通过扫描电镜(Scanning electron microscope,SEM)、能谱分析(Energy dispersive spectrometer,EDS)及X射线衍射(X-ray diffraction,XRD)对修复层微观组织、元素分布及物相组成进行观察分析;对激光熔覆修复层显微硬度进行测试;分别对修复层和KMN钢基体进行干摩擦滑动摩擦测试,观察并分析磨痕三维形貌;测得修复层及KMN钢基体的Tafel曲线,并使用Tafel直线外推法、失重法测试修复层与基体材料的腐蚀速度。结果表明,激光熔覆修复层与基体呈良好冶金结合、无气孔裂纹等缺陷;修复层硬度是基体材料的1.8倍;耐磨性、耐蚀性得到显著提升。
KMN steel is a kind of high-strength low alloy steel which commonly used in large centrifugal compressor impeller. It is often falled in service process caused by wear, corrosion and other damage. Laser cladding is an effective means to remanufacture of fallure impeller. Based on this, the FeCr alloy is deposited on KMN steel plate which had been preset defect by laser cladding. The microstructure, phase constitution, hardness and wear resistance of the clad layer are investigated by scanning electron microscope （SEM）, energy dispersive spectroscopy（EDS）, X-ray diffractometer, Vickers digital micro-hardness tester, sliding wear tester and optical profiler. The Tafel curves of repalred layer and KMN substrate are measured. The etching rate is analyzed for both of them. The results show that the recovered layer is free of cracks and has a good metallurgical bonding with substrate. The laser cladding repalred coating present a great hardness, excellent wear resistance and corrosion resistance.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2015年第8期37-43,共7页
Journal of Mechanical Engineering
基金
国家重点基础研究发展计划(973计划
2011CB013403)
泰山学者建设工程资助项目
关键词
激光熔覆
KMN钢
叶轮修复再制造
耐磨性
耐蚀性
laser cladding
KMN steel
impeller remanufacture
wear resistance
corrosion resistance
作者简介
赵彦华，男，1987年出生，博士研究生。主要研究方向为机械装备再制造。E—mail：zhaoyanhua_007@163．com
孙杰（通信作者），男，1967年出生，教授，博士研究生导师。主要研究方向为难加工材料高速切削机理、激光加工技术。E-mail：sunjie@sdu．edu．cn
