CAJ | 학술논문

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FeCr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。
KMN강시대형리심식압축궤협륜상용재료，복역과정중상출현마손、부식등손상도치실효，격광용복기술시실현손상협륜수복재제조적유효수단。사용FeCr합금분료통과격광용복기술재예치결함적KMN강기체상제득수복층。통과소묘전경(Scanning electron microscope, SEM)、능보분석(Energy dispersive spectrometer, EDS)급X사선연사(X-ray diffraction, XRD)대수복층미관조직、원소분포급물상조성진행관찰분석；대격광용복수복층현미경도진행측시；분별대수복층화KMN강기체진행간마찰활동마찰측시，관찰병분석마흔삼유형모；측득수복층급KMN강기체적Tafel곡선，병사용Tafel직선외추법、실중법측시수복층여기체재료적부식속도。결과표명，격광용복수복층여기체정량호야금결합、무기공렬문등결함；수복층경도시기체재료적1.8배；내마성、내식성득도현저제승。
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.