The Influence of Work Roll Material on the Corrosion Behavior of Hot-Rolled Aluminum-Manganese Alloys

Abstract

The tribological impact of the steel alloy employed as the work roll material during hot rolling on the surface quality and corrosion behavior of Al-Mn alloys was explored. AISI 52100, AISI D2 and AISI 440C steel work rolls with a surface roughness (Ra) of 0.1 µm were used to hot roll Al-Mn alloy specimens under similar conditions using a rolling tribo-simulator. Corrosion tests were then performed on the rolled Al-Mn specimens by immersing them in a 0.5 wt.% NaCl solution. Surface examination of the Al-Mn specimens after rolling revealed dark MgO-rich islands covering the surfaces of the AISI D2 and AISI 440C-rolled Al-Mn surfaces. These features were associated with the carbides observed protruding from the AISI D2 and AISI 440C steel surfaces. Subsequent corrosion tests revealed that these MgO-rich islands possessed a distinct influence on the corrosion behavior of the rolled Al-Mn surfaces. The frequency of occurrence and depth of the MgO-rich islands, which were dependent on the work roll material employed, influenced the initial and subsequent corrosion morphology detected on the Al-Mn surfaces. The preferential dissolution of the MgO-rich islands was detected as one of the corrosion mechanisms occurring during the early stages of corrosion.