电弧喷涂Zn-22Al-Mg-RE合金涂层的耐蚀性能

Corrosion Resistance of Zn-22Al-Mg-RE Coating Prepared by Twin Wire Arc Spraying

摘要:

采用电弧喷涂技术和自主研发的合金丝材在Q345基体上制备出Zn-22Al-Mg-RE合金涂层。通过SEM、铜加速乙酸盐雾试验、XRD和极化曲线来比较纯锌涂层和Zn-22Al-Mg-RE合金涂层的微观结构及耐蚀性能。结果表明，Zn-22Al-Mg-RE合金涂层相比于纯锌涂层结合强度提高了40%，在铜加速乙酸盐雾试验中出现第一锈点的时间延长1倍以上。电化学实验结果也表明合金涂层具备更优异的耐蚀性能。研究认为，Zn-22Al-Mg-RE合金涂层腐蚀产物中出现大量稳定致密的Zn6Al2(OH)16CO3·4H2O物相，是耐蚀性能提高的主要原因之一

Abstract:

Zn-22Al-Mg-RE alloy coating was prepared on Q345 steel substrate by arc spraying with alloy wires which were researched and designed independently. The microstructure and corrosion resistance of the Zn-22Al-Mg-RE alloy coating were investigated and compared with that of Zn coating by SEM, Copper-accelerated acetic acid salt spray, XRD and Polarization curves. Results show that the bonding strength of Zn-22Al-Mg-RE alloy coating is increased by 40% compared with that of pure zinc coating?, and the first rust appearing time is prolonged by 1 time in Copper-accelerated acetic acid salt spray test. Electrochemical experiment results show that the corrosion resistance of Zn-22Al-Mg-RE alloy coating is superior to that of pure Zn coating. It is indicated that the appearance of much Zn6Al2(OH)16CO3·4H2O which is stable and dense, is one of the main reasons for the enhanced corrosion resistance of the Zn-22Al-Mg-RE alloy coating