Experimental Research on Non-Magnetic Steel 30Mn27Al4V

Abstract

Non-magnetic steels are required in energy and transportation fields such as superconducting energy storage equipment, magnetic liquid power generation equipment, superconducting generators, superconducting power transmission and ship electromagnetic propulsion. Experimental research on steel making, hot rolling, solution and aging for non-magnetic steel 30Mn27Al4V was carried out in the laboratory. The microstructure evolution was observed and the mechanical property and relative magnetic permeability were tested after heat treatment. The effects of fine particles such as VC, VN and V(CN) dispersively distributed in austenite matrix on precipitation, grain refinement and austenitic nucleation were analyzed. The microstructure of the tested steel is austenite. The grain size is 24~28μm. At room temperature, the yield strength and tension strength are 556 MPa and 701 MPa, elongation after fracture of the steel is 47%, the yield ratio is 0.79, strength and ductility product is 32.9 GPa%. After solution and aging treatment, the steel shows a yield strength of 325~371 MPa, tension strength of 550~645 MPa, elongation of 58~78 %, a yield ratio of 0.54~0.60, strength and ductility product of 36.3~46.3 GPa%. The relative magnetic permeability is below 1.005. The results indicate that the tested steel exhibits good mechanical property and non-magnetism. It has no elements of Ni and Cr, so it just needs simple process flow and lower production cost. The numerous applications of the steel in industry can create great economic benefits.