含Cu耐候钢中稀土对耐蚀性的影响研究

Influence of Rare Earth on Corrosion Resistance Performance in Cu-Containing Weathering Steel

利用周期浸润加速腐蚀试验方法对10PCuRE和10PCu耐候钢进行了腐蚀试验。通过X射线衍射分析、电子探针和扫描电镜等手段对两种钢的表面锈层性能进行了研究,得到了10PCuRE钢致密锈层的种类、形成过程以及保护机理。通过对加稀土与未加稀土的耐候钢表面锈层的对比研究,可知10PCuRE钢的表面锈层比10PCu耐候钢的锈层要均匀致密,保护性能更好。稀土耐候钢的锈层分为两层,包括外锈层和均匀致密的内锈层,内锈层的组成相中超过80%为保护性的α-FeOOH。稀土促进了合金元素Cu在内锈层的富集,有利于保护性内锈层的生成,因而提高了钢基体的耐蚀性能。

Corrosion resistance of 10PCuRE and 10PCu steels was studied by dry-wet cycle immersion test.The performance of rust layer on 10PCuRE and 10PCu weathering steels was studied by XRD,EPMA and SEM.The kind,forming process and protection mechanism of the corrosion products of 10PCuRE are obtained.Results of the contrastive study of rust layer on rare earth weathering steel and weathering steel without rare earth show that the rust layer on 10PCuRE is more compact than the rust layer on 10PCu.The protective rust layer on 10PCuRE is divided into two layers including of outer rust layer and uniform compact inner rust layer.The 80% constituent phase of inner rust layer is steady α-FeOOH.The results indicate rare earth can promote alloying element Cu to enrich in the inner rust layer of 10PCuRE.The protective inner rust layer is easy to creating.So corrosion resistance of steel is improved.