오스테나이트계 18Mn강의 인공해수 내 부식 및 마모 거동

Abstract

This study examines the corrosion–wear behavior of microalloyed high-Mn steels and carbon steel in artificial seawater, focusing on the role of Cr. Microstructural characterization, electrochemical testing, weight-loss measurements, and molecular dynamics (MD) simulations were conducted. The Cr-containing 18Mn steel demonstrated superior electrochemical stability during the corrosion–wear process owing to the formation of Cr-rich oxides (e.g., Cr2O3, FexCr3-xO4)and their rapid reformation after mechanical damage from repeated wear. Consequently, it exhibited the lowest corrosion current density and the highest polar- ization resistance over 14 days of testing. In contrast, conventional 18Mn steel showed the greatest elec- trochemical activity and weight loss, exceeding those of carbon steel, due to accelerated Mn dissolution and repeated wear by coarse V-bearing carbides that degraded surface protection. MD simulations further revealed that, under aqueous conditions, Fe–Mn alloy system undergo greater atomic-scale surface dis- ruption than Fe–Cr alloy system, hindering the formation of stable interfacial oxides. These results elu- cidate the corrosion–wear mechanism and propose a viable alloying strategy to enhance the durability of offshore structural components exposed to cyclic wear and seawater environments.