Zn-Ni合金渗层的组织结构及腐蚀性能EI北大核心CSCD

为改善传统渗锌层组织结构及腐蚀性能,采用甲酸镍和锌粉作为渗剂金属,通过机械能助渗法在Q235钢表面制备Zn-Ni合金渗层。结合扫描电镜(SEM)、EDS能谱和X射线衍射仪(XRD),分析Zn-Ni合金渗层的表面、截面和断口形貌;利用极化曲线和电化学阻抗谱(EIS),表征Zn-Ni合金渗层在3.5%NaCl溶液中的电化学行为;通过中性盐雾试验测试Zn-Ni合金渗层的耐腐蚀性能。结果表明:制备得到Zn-Ni合金渗层的厚度为153μm;渗层主要由Γ(Fe_(11)Zn_(40))相、ζ(FeZn_(15))相和Ni_(2)Zn_(11)金属间化合物组成,渗层结合方式属于冶金结合;Zn-Ni渗层中性盐雾试验出现红锈的时间相比渗锌层延长240 h,自腐蚀电位从?1.222 V正移至?0.957 V,渗层电阻提高352?·cm^(2);Ni对改善渗层表面组织状态和提高渗层耐腐蚀性具有显著价值。通过添加甲酸镍制备的Zn-Ni合金渗层相比渗锌层组织结构和腐蚀性能得到明显改善。

Microstructure and Corrosion Properties of Zn-Ni Co-cementation Layer

In order to improve the structure and corrosion performance of the traditional sherardizing layer, nickel formate and zinc powder are used as the infiltrating agent metal, and the Zn-Ni cementation layer is prepared on the surface of Q235 steel by the mechanical energy assisted technology. The surface, cross-section and fracture morphology of the Zn-Ni cementation layer are characterized by scanning electron microscope (SEM), EDS spectroscopy and X-ray diffractometer (XRD); Electrochemical behavior of Zn-Ni cementation layer immersed in 3.5%NaCl solution is analyzed by polarization curve and electrochemical impedance spectroscopy(EIS). Corrosion resistance of Zn-Ni cementation layer is tested by neutral salt spray test. The results show that the thickness of the Zn-Ni cementation layer is 153 mu m; the layer is mainly composed of Gamma (Fe11Zn40) phase, zeta (FeZn15) phase and Ni2Zn11 intermetallic compound, cementation layer combination method belongs to metallurgical bonding. The neutral salt spray experiment of Zn-Ni cementation layer is longer 240 h than Zn cementation layer when appearing red rust spots, the self-corrosion potential move from -1.222 V to -0.957 V, impedance modulus of layer resistance is increased by 352 Omega . cm(2); Ni has significant value in improving the surface structure and the corrosion resistance of the infiltration layer. Comprehensively show that the Zn-Ni cementation layer prepared by adding nickel formate has significantly improved structure and performance compared to the sherardizing layer.