摘要
目的研究不同预热温度(200、400℃)条件下硬质颗粒增强镍基合金堆焊层的微观组织结构演化机理,以及对其力学性能、磨损性能的影响规律。方法采用等离子弧焊接技术在42CrMo钢基体表面堆焊硬质WC颗粒增强镍基强化层,利用X射线衍射(XRD)、扫描电子显微镜(SEM)、硬度计和摩擦磨损试验机,分析不同预热温度堆焊层的物相组成、微观组织形貌、力学性能和磨损性能,建立堆焊层制备工艺–微观组织结构–力学性能–磨损性能之间的强映射关系。结果堆焊层主要由γ-Ni/Fe、WC、W_(2)C、M_(7)C_(3)、M_(23)C_(6)、Ni_(2)W_(4)C、Cr_(3)C_(2)等物相组成,在预热温度200℃下堆焊层二次碳化物析出较少,发生了严重的WC颗粒沉降现象;在预热温度400℃下,堆焊层析出了大量的二次碳化物,WC颗粒沉降减弱,组织均匀性提高。在400℃下预热,相较于200℃下预热,堆焊层的磨损质量减少了51.85%,磨损率减少了51.89%。结论高预热温度和长保温时间可促进WC颗粒界面反应,驱动大面积二次碳化物的析出,有效缓解WC颗粒沉降,改善凝固组织中WC颗粒的分布均匀性,从而显著提高堆焊层的硬度和耐磨性。
Components in severe environment often fail to work due to abrasion,corrosion and fractures,surface strengthening technology has important applications in the fields of aerospace,steel and metallurgy.Nickel-WC is an ideal coating material for improving both wear resistance and corrosion resistance of components surfaces.However,WC bottom–concentrated situation generally occurs owning to large density of WC particles(16.5 g/cm3),which can cause stress concentration and increase the risk of cracking.WC bottom–concentrated situation is not desired in the fabricated process.In this study,WC particles reinforced Nickel alloy layers were prepared with different preheating schedule on 42CrMo steel substrate by powder plasma arc welding technology.The work aims to demonstrate the microstructure evolution of hard particle reinforced Nickel based alloy surfacing layers at different preheating temperature(200℃and 400℃)and investigate the effects on the mechanical and tribology properties.DML-V03BD was used to deposit the target surfacing layers.The 42CrMo steel was used as the substrate,which was cleaned with alcohol.Ni_(4)0A powder and 45%(mass fraction)WC particles added in Ni_(4)0A powder were used as the materials of bonding layer and hard layer,respectively.Before the deposition experiments,the substrate was executed at different preheating schedules of 200℃/30 min and 400℃/6 h.The bonding layer was deposited on the substrate firstly and the hard layer was deposited on the bonding layer then.The welding current used for bonding layer and hard layer was(140±10)A.The pendulum width was 20 mm.30%overlap rate between two single layers was executed.After the whole welding procedure,the samples were cooled to ambient temperature naturally.The phase composition was analyzed by X-ray diffractometer(XRD),the microstructure of the surface and cross-section of the samples was observed by scanning electron microscopy equipped with energy dispersive spectrometer(EDS)after standard metallographic etching procedures.The
作者
张春霖
张丽
李胜利
李静
张诗涵
解志文
ZHANG Chunlin;ZHANG Li;LI Shengli;LI Jing;ZHANG Shihan;XIE Zhiwen(School of Materials and Metallurgy,University of Science and Technology Liaoning,Liaoning Anshan 114051,China;School of Mechanical Engineering and Automation,University of Science and Technology Liaoning,Liaoning Anshan 114051,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2024年第9期127-136,共10页
Surface Technology
基金
国家重点研发计划(2021YFB3702003)。
