Cr_(3)C_(2)/WC的添加对Stellite 12熔覆层耐磨耐蚀性的影响  

Effect of Cr_(3)C_(2)/WC on Wear and Corrosion Resistance of Stellite 12 Cladding Layer

作　　者：赵菲[1] 张亮 吴志生[1] 温保安 ZHAO Fei;ZHANG Liang;WU Zhisheng;WEN Baoan(School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学材料科学与工程学院,太原030024

出　　处：《表面技术》2024年第1期135-142,共8页Surface Technology

基　　金：山西省基础研究计划(面上)(202303021211195)。

摘　　要：目的 提高Stellite 12熔覆层的耐磨耐蚀性能。方法将Stellite 12合金粉末与碳化物(Cr_(3)C_(2)、WC)混合,采用激光熔覆技术在H13钢板上制备复合熔覆层。通过超景深显微镜和XRD分析其显微组织和物相,通过显微硬度测试、摩擦磨损试验和电化学腐蚀试验,分别评价熔覆层的硬度、耐磨性和耐蚀性,并通过超景深显微镜对磨痕形貌进行分析。结果添加碳化物后,熔覆层的微观组织以柱状晶和树枝晶为主,物相主要由γ-Co固溶体和碳化物(M23C6、M7C3)组成;Cr_(3)C_(2)的添加使得熔覆层的硬度降低,由610HV0.2降至530HV0.2,但耐磨性得到提高,磨损量由0.45 mm^(3)降至0.33 mm^(3),下降了28%,耐蚀性得到提高,腐蚀电位由-0.385 V增加到-0.264 V,腐蚀电流密度由9.269×10^(-10)A/cm^(2)降至1.496×10^(-10)A/cm^(2),极化电阻由3.982×10^(7)Ω·cm^(2)提升至2.424×10^(8)Ω·cm^(2),提高了1个数量级;WC的添加使其硬度由610HV0.2提高至750HV0.2,磨损深度变浅,磨损量由0.45 mm3降至0.19 mm^(3),下降了43%,但耐腐蚀性有所降低。3种熔覆层的磨损机制主要为磨粒磨损和黏着磨损。结论WC的添加可以有效提高熔覆层的硬度和耐磨性,但耐腐蚀性有所降低;添加Cr_(3)C_(2)后,耐蚀性得到显著提高,耐磨性略微提升,但硬度降低。The properties of composite cladding layers prepared by laser cladding technology will vary considerably with the reinforcing phase.In order to study the effect of different carbide contents on the properties of the Stellite 12 cladding layer,the raw material used was Stellite 12 alloy powder with carbide(Cr_(3)C_(2) and WC).In addition,30 cm×30 cm×10 cm H13 steel was adopted as the substrate,on which Stellite 12,Stellite 12+10%Cr_(3)C_(2) and Stellite 12+10%WC were prepared by laser cladding technology.The three cladding layers of Stellite 12,Stellite 12+10%Cr_(3)C_(2) and Stellite 12+10%WC were then cut,ground and polished and corroded with aqua regia.The microstructures of layers were analyzed by ultra-deep field microscopy,the surfaces were examined by Xrd to analyze the physical phases and the hardness,wear resistance and corrosion resistance were evaluated by microhardness testing,friction wear testing and electrochemical corrosion testing,respectively.The wear scar morphology was also analyzed by ultra-deep field microscopy.The metallurgical results showed that the microstructures of the cladding layers were dominated by columnar crystals and dendrites after the addition of carbides,with the grain transformation from bottom to top being flat crystals to columnar crystals and then to dendrites and good metallurgical bonding at the surface of the bonding interface.Xrd inspection results showed that the three cladding layers had phases mainly composed ofγ-Co solid solution and carbides(M_(23)C_(6),M_(7)C_(3)),but the addition of WC led to the precipitation of Co_(6)W_(6)C and M_(7)C hard phases.In terms of microhardness,the melt layer of Stellite 12 was 610HV0.2,the addition of Cr_(3)C_(2) reduced the hardness of the melt layer to 530HV0.2 and the addition of WC increased its hardness to 750HV0.2.The wear performance was analyzed in terms of its average friction coefficient,wear profile and wear volume.The addition of Cr_(3)C_(2) reduced the average coefficient of friction from 0.32428 to 0.29187 and the w

关 键 词：激光熔覆 复合熔覆层 显微硬度 摩擦磨损行为 磨损机制 电化学腐蚀行为 

分 类 号：TG156.99[金属学及工艺—热处理]