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

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.