Double-phase twinborn induced plastic super-strength automobile steel plate and preparation method thereof

Abstract

The invention belongs to the technical field of automobile steel, and in particular relates to a double-phase twinborn induced plastic super-strength automobile steel plate and a preparation method thereof. The steel plate comprises the following chemical elements in percentage by weight: 0.3-0.6% of C, 8-12.00% of Mn, 1.00-3.00% of Al, less than or equal to 0.020% of P, less than or equal to 0.02% of S and the balance of Fe and inevitable impurities. The steel plate can be selectively cold-rolled with 5-25% of rolling reduction after warm-rolling at 100-250 DEG C, or a hot continuous rolled plate coil is cold-rolled after being softened and annealed. The yield strength of the steel plate is greater than or equal to 650MPa, the tensile strength is 1000-1500MPa, the extension rate of short continuous annealing is 15-25%, the product of strength and elongation is 20-35GPa%, the extension rate obtained after cover-type prolonged annealing is 25-40%, and the product of strength and elongation is 30-40GPa%.

Description

technical field [0001] The invention belongs to the technical field of production of steel plate coils for automobiles. It is a new steel grade invented based on a new material design principle. It has a dual-phase structure and is obtained through twin phase-twinning induced plasticity (DP-TWIP). Ultra-high strength and excellent plasticity, twin-induced plasticity, dual-phase automotive steel sheet and its preparation process. technical background [0002] In recent years, with the continuous improvement of automobile lightweight and safety performance requirements, the performance requirements of steel for automobile structural parts are also getting higher and higher, that is, high tensile strength and high elongation are required. This is mainly because auto parts usually need to be stamped and formed, so while improving the strength, it must have good ductility, so that the material still has good formability under high strength. Therefore, advanced high-strength stee...

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Problems solved by technology

As the second generation of advanced high-strength steel, the strength-plastic product of TWIP steel can reach 60GPa%, and industrial production has been realized. However, due to the high alloy content, industrial production is difficult and costly, and the problem of delayed cracking has been solved at present. The industrially applicable TWIP steel strength is about 1000MPa, and the strength needs to be improved, so it has not been widely used.

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