摘要
为研究Al-Zn-Si-RE合金涂层和相同Al含量的Al-Zn伪合金涂层耐蚀性能的不同,采用电弧喷涂技术在Q235钢表面制备了此两种合金涂层。通过盐水全浸实验和电化学测试技术对比研究了两种涂层的耐腐蚀性能,并将两种涂层的极化曲线与纯Zn、纯Al、Zn-15Al合金涂层进行了对比分析。使用扫描电镜、金相显微镜和X-射线衍射仪等手段测试分析了两种合金涂层腐蚀前后的微观组织形貌和相组成。结果表明,Al-Zn-Si-RE合金涂层的自腐蚀电位和自腐蚀电流密度分别为-0.995V和3.319×10-6 A/cm2,腐蚀电位更正,腐蚀电流密度更低,耐蚀性更好,原因可能是致密的腐蚀产物膜抑制了腐蚀作用;Al-Zn-Si-RE合金涂层与伪合金涂层微观组织成分和相结构的不同引起腐蚀行为的差异,且Al-Zn-Si-RE合金涂层表现出更好的耐盐水腐蚀性能;稀土元素的存在有利于提高Al-Zn-Si-RE合金涂层的耐蚀性。
Al-Zn-Si-RE coating and Al-Zn pseudo-alloy coating with the same Al content were deposited on mild steel by arc spraying to investigate their corrosion.The corrosion resistance of the two coatings was evaluated by comparing electrochemical measurement technique and being immersed in NaCl solution.Tafel curves of pure Zn,pure Al,and Zn-15 Al coatings and the two coatings were analyzed comparatively.X-ray diffraction technique（XRD）,optical microscope（OM）and scanning electron microscope（SEM）were used to study the microstructure and the composition of the corrosion products.Electrochemical measurement was carried out by Tafel and EIS.The results show that the ecorr and the corrosion current density of Al-Zn-SiRE coating are-0.995 Vand 3.319×10-6 A/cm2,Al-Zn-Si-RE coating has relatively higher ecorr,lower corrosion rate and better corrosion resistance,and the reason is that dense corrosion products restrain the corrosion.Different corrosion behaviors of Al-Zn-Si-RE and Al-Zn pseudo-alloy coating are due to the difference of their microstructure and phase structure.Al-Zn-Si-RE coating has better corrosion resistance of NaCl solution.RE in Al-Zn-Si-RE coating is in favor of improving the corrosion resistance of the coating.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2014年第6期58-66,共9页
China Surface Engineering
基金
江苏省科技成果转化专项基金(BA2011029)
江苏省普通高校研究生科研创新计划(CXLX12-0149)
