Rusting evolution and anti-corrosion mechanism of MnCuP weathering steel in simulated atmospheres

Abstract

This paper summaries the corrosion resistance of a low-cost MnCuP weathering steel in simulated coastal, industrial, and coastal-industrial atmospheric environments submitted to wet/dry cyclic acceleration corrosion tests. The results indicate that MnCuP weathering steel exhibits ideal corrosion resistance, and a protective rust layer can be formed on the steel with increasing the corrosion cycles in the three environments. The corrosion rate during the initial corrosion process is much higher than it is during the subsequent process. The corrosion rate decreases and then maintains at a steady decreasing value with prolonging the exposure duration. For mechanism, Mn and Cu contribute to the ion-selectivity of the rust layer formed in the coastal atmosphere. Cu and P are responsible for the enhanced atmospheric corrosion resistance in the industrial atmosphere. The combined effects of Mn, Cu, and P elements may be the key reason for the improved corrosion resistance of the steel in coastal-industrial atmosphere.