WC粒度对超音速火焰喷涂WC-10Co-4Cr涂层耐腐蚀性能的影响.pdfVIP

学兔兔 第2O卷第1期 粉末冶金材料科学与工程 2015年2月 、，oll20 NO．1 Materials Science and Engineering of Powder Metallurgy Feb．2015 WC粒度对超音速火焰喷涂WC．IOCo．4Cr 涂层耐腐蚀性能的影响 左晓婷，姚萍屏，贡太敏，肖叶龙，张忠义，赵 林，周海滨 (中南大学 粉末冶金国家重点实验室，长沙，410083) 摘 要：采用制粒～高温快速烧结法制备两种分别含亚微米级和微米级WC粒径的WC—lOCo．4Cr喷涂粉末，并用 超音速火焰喷涂(HVOF)技术在45 钢基体上制备涂层；利用扫描电子显微镜和电化学工作站分别对涂层的显微形 貌及耐腐蚀性能进行分析检测，探讨WC粒度对涂层耐腐蚀性能的影响和涂层的电化学腐蚀机理。研究结果表明： 两种涂层组织致密，界面结合良好；含亚微米级WC粒径的涂层具有相对较低的孔隙率，使其涂层的耐腐蚀性能 优于含微米级WC粒径的涂层。在3．5％NaC1溶液中涂层的硬质相WC和粘结相Co发生电偶腐蚀，且低电位的 Co相优先腐蚀，导致WC颗粒脱落，出现凹坑及点蚀现象。 关键词：超音速火焰喷涂；WC一1 0Co．4Cr；WC粒度；耐腐蚀性能；电化学 中图分类号：TG135．5 文献标识码：A 文章编号：1673—0224(2015)1—106—06 Effect 0f WC size on corrosion resistance of W C·10Co-4Cr coatings by high velocity oxygen fuel ZUO Xiao—ting，YAO Ping—ping，GONG Tai—rain，XIAO Ye—long，ZHANG Zhong-yi，ZHAO Lin，ZHOU Hai-bin (State Key Laboratory ofPowder Metallurgy,Central South University,Changsha 410083，China) Abstract：Two kinds of WC一10Co一4Cr comings on 45 steel substrate were fabricated by High Velocity Oxygen Fuel (HVOF)．The cemented carbide feedstock powders containing submicron WC and micron WC particle respectively were produced by the granulating and speedy high temperature sintering process．The microstructures and corrosion—resistance property of the coatings were studied，especially the corrosion processes and corrosion mechanisms were analyzed．The results show that compact microstructure and good coherence in interface of the coatings are obtained．The coating containing