【摘要】 研究了45钢氯系盐浴渗铬工艺与固溶渗氮预处理对盐浴渗铬试样耐蚀性的影响。结果表明,采用CaCl2-NaCl-NaF为基盐,以铬粉、铬盐和铬的氧化物为供铬剂,经850℃×6 h盐浴渗铬,可在试样表面获得20~30 mm厚的致密渗铬层。表层硬度1400~1700 HV0.3,渗铬样表层铬浓度为65%~90%。X射线衍射分析表明渗铬表层主要由Cr-Fe固溶体、铬的碳化物和少量氧化物组成。阳极极化曲线的测定分析表明,所有盐浴渗铬试样的耐蚀性普遍优于304不锈钢。其中固溶渗氮+盐浴渗铬复合处理试样的渗层钝化电流为(3.2~5.3)×10-5mA/cm2,远低于不锈钢和单一盐浴渗铬试样。更多还原

【Abstract】 The corrosion resistance and microstructure of the compound layer on 45 steel prepared by solid solution nitriding and molten salt chromizing were investigated.The results show that the compact chromizing layer with 20-30mm in thickness is obtained by using of molten salt chromizing at 850℃ for 6 h.The molten salt are composed of the CaCl2,NaCl,NaF,CrCl3,Cr2O3 and a little of chromium powder.The hardness and chromium content of the layer are 1400～1700HV and 65%～90%,respectively.The microstructures of the compound layer are mainly composed of Cr-Fe solid solution,Cr carbides and a little of oxides.Anode polarization curves show that,the corrosion resistance of the specimen treated in molten salt is better than that of 304 stainless steel.The best corrosion resistance of the layer is obtained by solid solution nitriding and molten salt chromizing,its passivation current of the layer is(3.2~5.3)×10-5mA/cm2 and very lower than that of 304 stainless steel and the specimen only treated by molten salt.更多还原