A kind of ultra-high strength medium manganese steel and its preparation method by warm rolling

Abstract

An ultra-high-strength medium-manganese steel and a warm-rolling preparation method thereof, wherein the chemical composition of the medium-manganese steel is calculated by weight percentage: C: 0.01-0.5%, Si: 0.1-3.0%, Mn: 6-10% , Al: 0.3-3%, P≤0.03%, S≤0.04%, and the rest are Fe and impurities. The preparation method comprises the following steps: (1) smelting; (2) hot rolling; (3) warm rolling; (4) annealing. The beneficial effects of the present invention are: the steel plate produced by the present invention has a tensile strength above 1200 MPa and a strength-plastic product greater than 30 GPa%, has low alloying cost, simple preparation, meets the needs of multiple industries such as automobiles and machinery, and has a wide range of product applications; Aiming at the characteristics of difficult cold deformation of ultra-high-strength hot-rolled sheets, the preparation process adopts warm rolling process, the deformation resistance of the material is small, the load of the rolling mill is lower, the wear on the rolls is reduced, and the grains are further broken and refined; The rolling process avoids problems such as the difficulty of large reduction in cold rolling and the need for long-term annealing before cold rolling, which reduces the production cycle, shortens the production line, and reduces production costs.

Description

technical field [0001] The invention belongs to the field of steel manufacturing for automobiles, and in particular relates to an ultra-high-strength medium manganese steel and a warm rolling preparation method thereof. Background technique [0002] Based on the requirements of the automotive industry for lightweight and high safety, people are paying more and more attention to the development of advanced high strength steel (AHSS) in the automotive field. At present, the application of advanced high-strength steel in the automotive field to achieve light weight of the car body is considered to be the key to improving fuel efficiency, and this will not adversely affect the safety performance of the car. The first-generation advanced high-strength steel has limited its application in the automotive field due to its low strength-plastic product (10-20GPa·%), while the second-generation advanced high-strength steel has a strength-plastic product of up to 50GPa·%, but its high a...

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Problems solved by technology

[0004] Aiming at the deficiencies in the prior art, the present invention provides an ultra-high-strength medium manganese steel and its warm-rolling preparation method, which avoids the problems of large reduction in cold rolling and long-term annealing before cold rolling. The deformation resistance is small, the load of the rolling mill is lower, the wear on the roll is reduced, and the grains are further broken and refined. The tensile strength of the medium manganese steel is above 1200MPa, and the strong-plastic product is greater than 30GPa·%.

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