The effect of drying-wetting alternation on corrosion resistance of rusted weathering steel

Abstract

In order to understand the effect of drying-wetting alternation on the corrosion resistance of rusted weathering steel, firstly, a rusted weathering steel was obtaioned through the preparation of stabilized rust layer on the surface of naked weathering steel; secondly, a cyclic corrosion test (CCT) of drying-wetting alternation with different cyclic periods was carried out for rusted weathering steel. With the extension of cyclic period in drying-wetting CCT, the corrosion resistance of rusted weathering steel increased from 0 cycle to 6 cycle and then decreased after 6 cycle, which was closely associated with the variations of composition and microstructure for stabilized rust layer during the process of drying-wetting CCT. From 0 cycle to 6 cycle, the increased corrosion resistance of rusted weathering steel was attributed to the abundance rise of α-FeOOH in the interior of stabilized rust layer; however, from 6 cycle to 20 cycle, the decreased corrosion resistance of rusted weathering steel was due to the partial destruction of crystal sturcuture for stabilized rust layer.