Temperature/shear-induced interface reconstruction of hot rolled carbon steel lubricated by polyphosphate composite lubricants

The present work aims to investigate temperature/shear-induced oxide reconstruction at the hot rolled steel interface, where sodium/potassium polyphosphates blended with different oxide nanoparticles were applied as the lubricant to control friction and manage oxidation. The lubrication of alkaline polyphosphate reduces the rolling force by up to 15% and prevents oxidation significantly. The undesired oxide scale can be transformed into iron oxide/alkaline polyphosphate composite imposed on hot rolled steel. Addition of inorganic oxide particles improves the consolidation and uniformity of reconstructed oxide layer. The polyphosphate formulations demonstrate the superiority of eliminating red scale over silicon alloyed steel. The mechanism of temperature/shear-induced interfacial transformation of the hot rolled steel associated with the interactions between oxide scale and alkaline polyphosphate constituent was discussed.