摘要
High corrosion-and wear-resistant stainless steels are highly sought after for demanding marine struc-tural applications.However,most stainless steels with high hardness or outstanding self-lubrication ex-hibit inferior corrosion resistance,and vice versa.In this study,we propose a strategy for wrapping oxide inclusions with the lubricating phase h-BN through in-situ nitrogen alloying in B-bearing stainless steel,forming a novel oxide@h-BN core-shell structure.The oxides exhibited constrained growth within the h-BN shell,which reduced the particle size and increased the number density.This modification enhanced dispersion strengthening,yielding a composite material hardness of 728 HV_(0.5).The h-BN functioned as a solid lubricant during the wear process,significantly lowering the friction coefficient.Additionally,the high electrical insulation and chemical stability of h-BN effectively separated the oxides from the sur-rounding matrix,thereby preventing pitting corrosion,which is typically associated with oxide dissolu-tion.The increased nitrogen content in the solid solution also enhanced the content of Cr_(2)O_(3)and CrN in the passive film,thereby improving its stability and protective capabilities.As a result,the corrosion re-sistance of this alloy was nearly comparable to that of 316 L stainless steel,whereas its wear performance surpassed that of M2 tool steel.Our findings offer valuable insights into the design of high-performance stainless steels.
基金
financially supported by the National Key Re-search and Development Program of China(No.2023YFB4603400).
