热丝激光熔覆Cr-W-Mo-V钢涂层组织与腐蚀磨损性能  

Microstructure and Tribocorrosion Properties of Cr-W-Mo-V Coating Fabricated via Laser Hot-wire Cladding

作　　者：王彦芳 周雪景 宋子翰 石志强 WANG Yanfang;ZHOU Xuejing;SONG Zihan;SHI Zhiqiang(School of Materials Science and Engineering,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)材料科学与工程学院,青岛266580

出　　处：《中国表面工程》2024年第3期25-36,共12页China Surface Engineering

基　　金：山东省自然科学基金(ZR2019MEM032)。

摘　　要：随着海洋油气资源的开发,钻采装备面临腐蚀与磨损的耦合损伤。开发耐磨耐蚀涂层材料及制备技术是海洋装备安全、可靠运行的保障。利用热丝激光熔覆技术在20钢基材表面制备Cr-W-Mo-V钢涂层,通过光学显微镜(OM)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)等分析涂层的显微组织和相组成,采用往复电化学腐蚀摩擦磨损试验仪分析涂层的干摩擦、电化学腐蚀及在3.5 wt.%NaCl溶液中的腐蚀磨损行为。制备的涂层组织均匀、致密,无裂纹、气孔等缺陷,主要由碳化物、马氏体和残余奥氏体组成,显微组织主要为柱状晶和胞状晶。涂层的平均硬度约为780 HV_(0.1),约是基材硬度的6.5倍,自腐蚀电位为-0.386 V,自腐蚀电流密度为3.45×10^(-6)A/cm^(2),具有优异的耐蚀性。在3.5 wt.%NaCl溶液中,随摩擦载荷的增大,涂层的开路电位下降,摩擦因数下降,腐蚀电流密度增大,摩擦对腐蚀有明显促进作用。随外加电位增加,涂层腐蚀电流密度增大,摩擦因数降低。热丝激光熔覆技术制备的Cr-W-Mo-V钢涂层结构致密、组织均匀,具有优异的腐蚀磨损性能,可用于海洋油气钻采装备在腐蚀磨损苛刻环境下零部件的表面改性。Owing to the development of marine oil and gas resources,drilling and exploitation equipment are affected by coupled damage from corrosion and wear.The development of wear-and corrosion-resistant coating materials as well as preparation technologies guarantees the safe and reliable operation of marine equipment.Laser cladding is a promising surface modification technology that is widely used in machine-component repair and functional coatings.However,the limitations of the deposition and material-utilization rates of the conventional laser cladding technology restrict its widespread use.Laser hot-wire cladding(LHWC)is a promising,efficient,and energy-saving coating-deposition process.In this study,Cr-W-Mo-V steel coating is prepared on the surface of a 20 steel substrate using LHWC technology.The microstructure and phase composition of the coating are analyzed using a ZEISS optical microscope,an XRD-7000 X-ray diffractometer,and a JSM-7200F scanning electron microscope.The microhardness of the coating is measured using an HV-100A microhardness tester.The dry friction factor,polarization curve,and electrochemical impedance of the coating are measured using a reciprocating electrochemical corrosion friction and wear tester(MFT-EC4000,HUAHUI).The loss of wear marks is measured using three-dimensional morphometry,and the microscopic morphology and elemental distribution of the wear marks are observed using scanning electron microscopy and energy dispersive spectroscopy.The open potential,dynamic polarization curve,and constant-potential polarization curve of the coating at various friction load in 3.5 wt.%NaCl solution are analyzed and the tribocorrosion mechanism is discussed.The prepared Cr-W-Mo-V steel coating is uniform and compact-without cracks,pores,or other defects-and is primarily composed of carbide,martensite,and residual austenite phases.The microstructures are primarily columnar and cellular crystals.The average hardness of the cladding layer is 780 HV0.1,which is approximately 6.5 times the hardness of

关 键 词：热丝激光熔覆 Cr-W-Mo-V钢涂层 显微组织 腐蚀磨损 

分 类 号：TG156[金属学及工艺—热处理] TB114[金属学及工艺—金属学]