Medium temperature deformation nanometer austenite enhanced plasticized steel and preparation method thereof

Abstract

The invention provides a medium temperature deformation nanometer austenite enhanced plasticized steel and a preparation method thereof, belonging to the technical field of high-strength high-plasticity automobile steel sheet materials, section bars and rods and wires. The steel comprises the following chemical components by mass: 0.03 to 0.39 wt% of C, 2.0 to 9.0 wt% of Mn, 0 to 2.0 wt% of Al, 0 to 2.0 wt% of Si, 0 to 2.0 wt% of Cr, no more than 0.020 wt% of P and no more than 0.02 wt% of S, with the balance being Fe and unavoidable impurities. The steel may further comprise one or more elements selected from the group consisting of 0.1 to 3.0 wt% of Ni, 0.1 to 0.8 wt% of Mo, 0.5 to 2.0 wt% of Cu, 0.0005 to 0.005 wt% of B, 0.02 to 0.10 wt% of Nb, 0.002 to 0.25 wt% of N, 0.05 to 0.25 wt% of Ti, 0.02 to 0.25 wt% of V, 0.002 to 0.005 wt% of RE and 0.005 to 0.03 wt% of Ca. The invention has the following advantages: sizes of austenite and ferrite of the steel are in a range of 50 to 250 nm; low cost, easy production, high strength and high plasticity are realized; the steel has yield strength of 0.6 to 1.3 GPa, tensile strength of 1.0 to 1.5 GPa and plasticity of 20 to 50% and has good low-temperature toughness.

Description

Technical field [0001] The invention belongs to the technical field of high-strength and high-plasticity automobile steel plates, profiles and rods and wires, and in particular provides a medium-temperature deformed nano-austenite reinforced plasticized steel and a preparation method thereof, which stabilize and refine metastable austenitic steel through medium-temperature deformation Nano-austenite and ferritic dual-phase steel. The austenite and ferrite size of the steel is in the 50-250nm grade, low cost and easy to produce, with high strength and high plasticity, its yield strength is 0.6GPa-1.3GPa, and its tensile strength is 1.0GPa-1.5GPa. Plasticity is 20-50%. At the same time, because the grain size is refined to the nanometer level, the steel has high low temperature toughness. technical background [0002] With the development and progress of society, the development of the automobile industry has made a huge leap, and the requirements and standards of automobile stee...

AI Technical Summary

Problems solved by technology

Traditional hot rolling can refine grains, but its refining ability is limited, and it can reach the level of 10μm level, resulting in poor plasticity and toughness

Traditional cold rolling can increase the strength of steel by reducing grain size and increasing dislocations, but the plasticity of steel will be greatly reduced. Generally, the plasticity of cold rolled steel is only at the level of 10%, which is not conducive to the further forming of steel plates.

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