激光熔覆Fe-Ti-V-C合金微观组织与磨损性能

发布时间：2018-04-23 02:04

本文选题：激光熔覆 + 耐磨性　；参考：《机械工程学报》2017年02期

【摘要】：采用激光熔覆技术在20G基体上制备五组不同Ti质量分数的Fe-Ti-V-C系合金,利用金相显微镜、扫描电子显微镜、X射线衍射仪、显微硬度计和磨料磨损试验机等仪器对各熔覆层的显微组织、硬度和耐磨性进行测试和分析。试验结果表明:五组合金熔覆层基体组织均由铁素体和马氏体构成;随着熔覆层中Ti质量分数的增加,针状马氏体基体组织转变为板条马氏体;初生(Ti,V)C的形态由树枝状和花瓣状向颗粒状转变,同时碳化物(Ti,V)C的数量逐渐增多,当Ti质量分数为14.7%时,碳化物的数量达到最高值。熔覆层截面显微硬度梯度分布合理,表层硬度达到700~950 HV0.2。湿砂磨粒磨损试验表明:适量Ti显著提高了熔覆层的耐磨性,熔覆层中随着Ti质量分数的提高,耐磨性先降低后提高,当Ti质量分数为14.7%时,大量颗粒状(Ti,V)C均匀弥散分布在铁素体及板条马氏体基体上,使得熔覆层具有最佳的耐磨性。
[Abstract]:Five groups of Fe-Ti-V-C alloys with different Ti mass fraction were prepared on 20G substrate by laser cladding technique. Metallographic microscope, scanning electron microscope and X-ray diffractometer were used. The microstructure, hardness and wear resistance of each cladding layer were tested and analyzed by microhardness tester and abrasive wear tester. The results show that the matrix structure of the five alloy cladding layers is composed of ferrite and martensite, and the acicular martensite matrix changes into lath martensite with the increase of Ti mass fraction in the cladding layer. The morphology of the primary TiGV C changed from dendritic and petal to granular, while the number of the carbides increased gradually. When Ti mass fraction was 14.7wt%, the number of the carbides reached the highest value. The microhardness gradient distribution of the cladding cross section is reasonable, and the surface hardness reaches 700 ~ 950 HV0.2. The results of wet sand abrasive wear test showed that proper amount of Ti increased the wear resistance of the cladding layer. With the increase of Ti mass fraction, the wear resistance of the cladding layer decreased first and then increased, and when the Ti mass fraction was 14.7%, the wear resistance of the cladding layer decreased first and then increased, when the Ti mass fraction was 14.7%, A large number of granular tio VZC dispersed uniformly on ferrite and lath martensite matrix, which made the cladding layer have the best wear resistance.
【作者单位】：沈阳化工大学机械工程学院;
【基金】：辽宁省博士科研启动基金资助项目(20141082)
【分类号】：TG174.4

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