电弧离子镀CrN涂层盐雾腐蚀行为

来源期刊：金属学报2010年第5期

论文作者：万先松 师玉英 马军 李海庆 宫骏 孙超

文章页码：600 - 606

关键词：CrN； 电弧离子镀； 盐雾腐蚀； 动电位极化曲线

Key words：CrN； arc ion plating； salt spray corrosion； potentiodynamic polarization

摘    要：采用电弧离子镀技术在38CrA调制钢上制备CrN涂层,分析了涂层的组织及结构,研究了工艺参数对CrN涂层中性盐雾腐蚀性能的影响.结果表明:3组不同工艺的CrN涂层均由fcc-CrN,hcp-Cr₂N以及bcc-Cr相组成;在N₂压强较低时,CrN相表现为{100}择优取向,N₂压强较高时,则表现为{110}择优取向.在高偏压低N₂压强下沉积的CrN涂层结构致密,残余应力和孔隙率最小,具有最佳的抗盐雾腐蚀性能.通过扫描电子显微镜分析盐雾腐蚀后样品的表面腐蚀产物,并结合极化曲线测量结果,对其盐雾腐蚀机理进行了探讨.

Abstract: CrN coatings were deposited onto 38CrA substrate using arc ion plating (AIP) method. The microstructures of CrN coatings were investigated by XRD and SEM.The corrosion behaviour affected by deposition parameters was studied by salt spray corrosion test in a neutral mist of NaCl solution at (35±2)℃ for 300 h.The results show that all of the CrN coatings contain primarily fcc-CrN along with hcp-Cr₂N and bcc-Cr phases.CrN phase in coating deposited under lower N₂ pressure exhibited {100} preferred orientation,while {110} preferred orientation under higher N₂ pressure. Under the deposition condition of higher bias voltage and lower N₂ pressure,the CrN coating achieves dense microstructure with less residual stress and porosity,which leads to better corrosion resistance in salt spray test.The corrosion product of salt spray test was investigated by SEM and EDS,and the corrosion mechanism was discussed.