High-strength and high-plasticity 1000mpa grade hot-rolled steel plate and preparation method thereof

Abstract

The invention discloses a high-strength and high-plasticity 1000 Mpa grade hot rolled steel plate and a preparation method thereof. The high-strength and high-plasticity 1000 Mpa grade hot rolled steel plate is prepared from the following components by weight: 0.05%-0.40% of C, 1.00%-5.00% of Mn, 0.70%-1.60% of Si, 0.1%-1.00% of Al, 0.01%-0.10% of Nb, 0.01%-0.10% of V, 0.002%-0.005% of N and the balance Fe and inevitable impurities. The steel plate has high strength and high plasticity, and Nb and V microalloy elements are added to be combined with C and N to form nanoscale cluster precipitates, so that matrix structures are strengthened. Through chemical composition design, and combined with medium temperature coiling, the nanoscale cluster precipitates with small size, uniform distribution and high density can be obtained, the strength of ferrite is obviously strengthened, the strength difference between the two matrix structures (ferrite and martensite) is reduced, the ferrite grainsize is refined at the same time, and high reaming performance is obtained.

Description

technical field [0001] The invention relates to the technical field of high-strength hot-rolled steel for automobiles, in particular to a high-strength and high-plasticity 1000MPa grade hot-rolled steel plate and a preparation method thereof. Background technique [0002] With the increasingly stringent national environmental protection laws and regulations and the implementation of the country's restrictions on automobile emissions, in the field of automobiles, especially passenger cars, high-strength thinning or lightweight automobile structures have become an important research direction for international automobile manufacturers. [0003] The thickness of the steel plates used for automobile body-in-white is mostly less than 3mm. For high-strength steels with a tensile strength greater than 1000MPa, they are generally used in structural parts. The stamping performance of steel plates is not high, but sufficient elongation and hole expansion performance must be guaranteed....

AI Technical Summary

Problems solved by technology

[0007] Most of the existing precipitation-strengthened steel plates on the market meet the requirements in terms of mechanical properties, but for steel plates with a strength ≥ 1000 MPa, due to the low strength of ferrite, there is a large gap between the strength of the other structure (martensite or bainite) The hole expansion performance is poor and cannot meet the user's forming requirements

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