Low-temperature colossal carbon supersaturation enables anti-wear boundary film formation for austenitic stainless steels in oil-lubricated environment

► Low-temperature carburization demonstrated an improvement of wear-resistance by three orders of magnitude for austenitic stainless steel in a fully-formulated engine oil. ► A 20 nm thick, anti-wear boundary film was detected on the worn carburized surface as a product of tribochemical interactions with the lubricant additives, particularly ZDDP. ► Surface chemical analysis revealed the changes of film spatial distribution and composition depth profile during the wear process as initial mechanistic understanding of the dynamic process of the boundary film formation and progression.