Titanium and molybdenum content in supermartensitic stainless steel

The supermartensitic stainless steels (SMSS) must be developed considering a balance between strength and toughness that are achieved by controlling the chemical compositions and heat treatment. In this paper, the results of detailed investigations on 12.50 Cr–5.40 Ni–2.10 Mo–0.13 Ti SMSS composition were obtained after the SMSS was put in a vacuum furnace and subsequently hot rolled and heat-treated. A very fine microstructure of martensite matrix with nanometer size particles of titanium carbonitride (Ti(C, N)-70 nm) was selected after quenching and tempering. Such microstructure reasonably showed an improved mechanical property values: 28 RC hardness, 804 MPa tensile strength, 764 MPa yield strength, 23.7% elongation and 256 J impact energy.