An Evaluation of the Influence of Forward Slip on the Corrosion Behavior of Aluminum-Manganese Alloys

Abstract

The tribological influence of hot rolling parameters, such as the work roll roughness, roll speed, and the number of rolling passes on the surface quality of rolled aluminum alloys, has been a subject of interest for the wrought aluminum industry. A hot rolling tribo-simulator was used to investigate the effect of forward slip on the surface damage induced by the rolling operation and the subsequent corrosion behavior of the Al-Mn alloys. A two-pass hot rolling schedule was conducted at 500–540 °C for forward slip levels of − 4, 1, 7, and 13% using an AISI 52100 steel work roll with a surface roughness (Ra) of 0.01 µm. Characterization of the rolled surfaces using scanning electron microscopy (SEM) revealed hot rolling-induced damage in the form of microcracks, nanocracks, and MgO coverage, which was more prominent for higher forward slips. Corrosion tests were subsequently conducted on the rolled Al-Mn specimens by immersion in a 0.5 wt.% NaCl solution. These tests showed greater corrosion-covered surface areas on samples rolled at lower forward slips. This relationship between the forward slip and corrosion behavior was due to the extent of surface damage induced at varying forward slip levels. The preferential corrosion mechanism was observed to be due to the dissolution of the MgO-rich near-surface microstructures induced during hot rolling.