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为了提高28CrMo钢表面的致密性和耐腐蚀性能,采用磁控溅射技术在28CrMo钢表面制备TiN涂层,通过光学显微镜、X射线衍射仪(XRD)、电化学测试等手段分析了TiN涂层的显微结构及其在3.5 ％NaCl溶液中的耐腐蚀性能.结果表明:采用磁控溅射技术在28CrMo钢表面制备了厚约0.5 μm的TiN涂层,涂层与基体结合良好,没有出现明显的裂纹,涂层表面N的原子分数明显高于Ti;电化学Nyquist谱得到高频区的容抗弧可能是由电荷转移电阻引起和膜层引起,中频区的容抗弧由基体金属溶解时的传质弛豫引起,低频区的感抗弧由基体表面吸附物的弛豫过程引起;3.5 ％NaCl溶液中腐蚀96 h后TiN涂层表面有蚀坑,吸附有白色疏松的腐蚀产物,并出现大小不一的腐蚀坑;TiN涂层能够明显改善基体的耐蚀性能,对改进高铬钢表面特性具有重要的作用.

In order to improve the compactness and corrosion resistance of 28CrMo steel surface,the TiN coating on 28CrMo steel surface was plated by magnetron sputtering technology.The microstructure and corrosion resistance of TiN coating in 3.5 ％ NaCl solution were tested by optical microscope,X-ray diffractometer (XRD) and electrochemical testing methods.Results showed that the thickness of TiN coating on 28CrMo steel surface plated by magnetron sputtering technology was about 0.5 μm.The coating had a good combination with the substrate,and no obvious cracks were observed.The atomic percentage of N on the coating surface was obviously higher than that of Ti.Besides,the capacitive reactance arc of high frequency area in electrochemical Nyquist diagram might be caused by the charge transfer resistance and membrane layer.The capacitive reactance arc of intermediate frequency might be caused by mass transfer relaxation matrix metal dissolve.The impedance arc of low frequency might be caused by the relaxation process of adsorbate on the substrate surface.Furthermore,in 3.5％ NaCl solution,the TiN coating was completely corroded after corrosion test for 96 h,and white and loose corrosion products as well as some corrosion pits were observed.In general,the TiN coating could significantly improve corrosion resistance of the substrate,which played an important role in the modification of high chrome steel surface features.