304不锈钢表面激光熔覆Inconel625涂层组织与性能分析  

Analysis on Organization and Properties of Laser Clad Inconel625 Coating on 304 Stainless Steel Surface

作　　者：秦明军 孙文磊[1] 管文虎 吴文宁 朱理想 林红波 QIN Mingjun;SUN Wenei;GUAN Wenhu;WU Wenning;ZHU Lixiang;LIN Hongbo(College of Intelligent Manufacturing Modern Industry,Xinjiang University,Urumqi 830017,China)

机构地区：[1]新疆大学智能制造现代产业学院,乌鲁木齐830017

出　　处：《表面技术》2024年第15期141-151,共11页Surface Technology

基　　金：新疆维吾尔自治区重点实验室开放基金(2020520002);新疆维吾尔自治区重点研究项目(2022B01036);新疆维吾尔自治区科研创新项目(XJ2022G011)。

摘　　要：目的解决不锈钢零部件在热电厂中由于腐蚀和磨损造成的资源浪费和设备报废等问题,通过表面改性的方式来提高不锈钢零件的耐磨耐腐蚀性能。方法利用激光熔覆技术在304不锈钢表面制备Inconel625涂层,利用工业显微镜、扫描电镜、X射线衍射仪、超景深仪器等设备,系统地探究熔覆层表面形貌、显微组织、元素分布、表面粗糙度。采用显微硬度计、摩擦磨损仪、电化学工作站等设备,检测熔覆层的硬度分布规律、耐磨和耐腐蚀特性。结果单因素试验最佳工艺参数为激光功率1200 W、送粉率10 g/min、扫描速度14mm/s。熔覆层底部到顶部组织,主要以不同形态的典型树枝晶组织为主,以及少量胞状晶。熔覆层物相组成主要包括FeCr_(0.29)Ni_(0.16)C_(0.06)、NbC、Cr_(2)Ni_(3)、Mo_(2)C。涂层硬度较基体大幅提升,涂层最高硬度值达425.48HV0.2,约为基体的1.8倍,涂层的磨损量为2.4 mg,约为基材磨损量(4.4 mg)的55%,摩擦系数平稳,变化幅度较小,耐磨性能较基体显著提高。电化学腐蚀试验后,基体开路电位为–0.44 V,熔覆层开路电位稳定在–0.17V,较基体偏正。涂层的自腐蚀电位(Ecorr)为–1.00V,大于基体的自腐蚀电位(–1.10V),涂层的自腐蚀电流密度(Jcorr)为3.47×10^(–8)A/cm^(2),小于基体的自腐蚀电流密度(6.43×10^(–8)A/cm^(2)),从而得出涂层腐蚀倾向较基体小。涂层的电容弧半径大于基体,该频率范围内涂层的阻抗模量均大于基体,表明涂层的耐腐蚀性能更好。结论Inconel625合金涂层能够显著提高304不锈钢的表面硬度、耐磨耐腐蚀性能。Laser cladding technology has many advantages over traditional surface modification methods,including complete metallurgical bonding,low heat input process,small heat-affected zone,low dilution rate,high solidification rate,and the ability to prepare thin and light coatings.Therefore,in order to improve the surface modification of stainless steel parts and improve the wear and corrosion resistance of stainless steel parts in cogeneration plants due to the waste of resources and equipment scrap caused by corrosion and wear,laser cladding was used to improve the wear and corrosion resistance of stainless steel parts.The laser cladding technology was used to prepare Inconel625 coating on the surface of 304 stainless steel.Industrial microscope,scanning electron microscope,X-ray diffractometer,ultra-depth of field instrumentation and other equipment were used to systematically explore the surface morphology of the cladding layer,microstructure,elemental distribution,and surface roughness.Microhardness tester,friction and wear equipment,electrochemical workstation and other equipment were used to test the hardness distribution pattern,wear and corrosion resistance of the fused cladding layer.In the single-factor test,the minimum dilution rate and the best macroscopic appearance were taken as the optimization basis,which led to the optimal process parameters of laser power 1200 W,powder feeding rate 10 g/min,scanning speed 14 mm/s.The bottom to top organization of the fused cladding layer with optimal parameters was mainly dominated by typical dendritic crystal organizations with different morphologies,as well as a small amount of cytosolic crystals.The physical phases mainly consisted of FeCr_(0.29)Ni_(0.16)C_(0.06),NbC,Cr_(2)Ni_(3),Mo_(2)C,etc.Compared with the substrate,the coating hardness was greatly improved,the highest hardness value of the coating reached 425.48HV0.2,which was about 1.8 times the substrate.The main reason was due to the rapid heating and cooling process,resulting in the surface organization of

关 键 词：激光熔覆 显微组织 显微硬度 304不锈钢 电化学腐蚀 摩擦磨损试验 

分 类 号：TG174.4[金属学及工艺—金属表面处理]