Study on Preparation and Properties of Resource-Saving Nitrogenous Stainless Steel

Abstract

In order to alleviate the shortage of global nickel resources, it is imperative to develop low nickel stainless steel. This paper presents a novel approach based on increasing nitrogen and reducing nickel for smelting economical stainless steel. Taking 06Cr19Ni10 stainless steel as the object, the test steels with different nitrogen and nickel content were smelted using vacuum induction furnace (ZG-0.01) under the laboratory conditions, and the effects of alloy content on microstructures, mechanical properties and corrosion properties of the economical stainless steel were investigated. The results show that the microstructure of the tested steel which nitrogen content 0~0.28% and nickel content 5.98~9.63% is still the single austenitic, and the grain size decreases as the nitrogen content increases. Nitrogen deteriorates the impact toughness of the tested steel, and the room temperature impact absorption energy is reduced from 267 J at the nitrogen content of 0 to 228 J at nitrogen content of 0.28%. Rockwell hardness, tensile strength and yield strength increase with the increase of nitrogen content. When the nitrogen content is 0.28%, the optimum mechanical properties of 06Cr19Ni10 steel are obtained. The Rockwell hardness is 95.4 HRB, the tensile strength is 814 MPa, the yield strength is 437 MPa, and the elongation after fracture is 52.5%. The degree of intergranular corrosion of the tested steel is reduced significantly with the increase of nitrogen content, from 0.023 μm to 0.008 μm. The experimental data prove that the composition design concept of increasing nitrogen and reducing nickel is feasible for smelting economical stainless steel.