Martensite transformation induced by plasma nitrocarburizing on AISI304 austenitic stainless steel

• Martensite transformation is induced by plasma nitrocarburizing in AISI304 steel.
• The initial transformation microstructure presents as nanoscale qusai-pealite.
• The martensite transformation layer possesses high hardness and good ductility.

In this paper, martensite transformation induced by plasma nitrocarburizing in AISI304 austenitic stainless steel is investigated. The optical micrographs and XRD results indicate the dual-layer structure of the nitrocarburized layer: the outer martensite transformation layer and the inner C supersaturated austenite layer. The initial transformation microstructure presents as nanoscale qusai-pealite which is composed of α′-martensite and NaCl-type MX (M = Cr, Mn, Fe, Ni; X = C, N) phase. The martensite transformation layer possesses high hardness and good ductility.