超音速喷涂Cr_3C_2-25NiCr复合涂层的组织及电化学特性研究  

Microstructure and Electrochemical Properties of Cr_3C_2-25NiCr Coating by HVOF spraying

作　　者：沈婕[1] 国俊丰[1] 魏伟[1] 高峰[1] 万伟伟[1] 侯伟骜[1] 

机构地区：[1]北京矿冶研究总院,北京100044

出　　处：《热喷涂技术》2009年第2期48-52,共5页Thermal Spray Technology

摘　　要：采用超音速火焰喷涂(HVOF)设备在Q235钢表面制备了Cr3C2-25NiCr金属陶瓷涂层,对涂层的显微形貌、组织成分和机械性能进行了研究,结果表明:HVOF制备出的金属陶瓷涂层主要由NiCr、Cr3C2和Cr7C3相组成,涂层致密、硬度高,与基材的结合强度好。实验还测试了涂层和基材在0.5%H2SO4溶液中的腐蚀、电化学行为,阳极极化曲线测试结果显示出涂层在0.5%H2SO4溶液中具有很好的耐蚀性,通过SEM及所配能谱对基材和涂层腐蚀产物形貌和成分进行分析,发现涂层腐蚀主要发生粘结相NiCr合金处,而Ni、Cr氧化物阻止了腐蚀进一步发生,96h浸泡实验也证实了致密的金属陶瓷涂层对基材有很好的抗腐蚀保护作用。Cr3C2-25NiCr metal ceramic coating was produced on the surface of Q235 steel by HVOF(high velocity Oxy-fuel)spraying. The micro-morphology,composition,mechanical properties of coatings were studied. The results show that the coating are mainly composed of NiCr,Cr3C2 and Cr7C3 phases. It is dense with high hardness and good bond strength with the substrate. The corrosion and electrochemical properties of the coating and substrate were also tested in 0.5% H2SO4 solution. Anodic polarization curves of the test show the coating in 0.5% H2SO4 solution has excellent corrosion resistance performance. The morphologies,compositions of the substrate and corrosion product were analyzed by means of SEM and EDX,which demonstrate the corrosion of coating mainly existed in binder phase NiCr alloy,at the same time,Ni,Cr oxide prevented further corrosion. 96h soaking experiments also confirms dense metal ceramic coating had a good property of anti-corrosion on the substrate.

关 键 词：HVOF Cr3C2–25NiCr涂层 显微组织 电化学 

分 类 号：TG174[金属学及工艺—金属表面处理]