Niobium-containing high-strength hot-galvanized steel plate and production method thereof

Abstract

The invention relates to a niobium-containing high-strength hot-galvanized steel plate and a production method thereof. The invention provides a high-gamma-average-value low-Delta gamma-value structural niobium-containing high-strength hot-galvanized steel plate and a manufacturing method thereof. The niobium-containing high-strength hot-galvanized steel plate comprises the following components in percentage by mass: 0.03-0.1% of C, at most 0.05% of Si, 0.5-0.9% of Mn, at most 0.025% of P, at most 0.015% of S, at most 0.005% of N, at most 0.005% of Ti, 0.03-0.06% of Nb, 0.01-0.08% of Al, and the balance of Fe and inevitable impurities. The preparation method comprises the following steps: carrying out hot rolling on a steel billet, reeling, and carrying out acid washing, cold rolling, and carrying out hot galvanizing. The gamma average value of the Nb-containing high-strength hot-galvanized steel plate is greater than or equal to 1.3, the Delta gamma value is less than or equal to 0, the yield strength is greater than or equal to 460 MPa, the tensile strength is greater than or equal to 570 MPa, and the elongation at break is greater than or equal to 28%. The invention can ensure favorable forming property on the premise of ensuring high strength.

Description

A kind of niobium-containing high-strength hot-dip galvanized steel sheet and its production method technical field The invention belongs to the technical field of metal materials and their preparation, in particular to high-strength hot-dip galvanized steel sheets containing niobium for structures and a production method thereof. Background technique The use of high-strength steel plates is a major development trend of modern automotive steel. Generally speaking, as the strength of the steel plate increases, the formability decreases. It is a common wish of the automobile and steel industries to develop steel plates with both high strength and excellent formability. The plastic strain ratio (γ, Δγ value) is an important index to measure the formability of thin steel plates. The γ value is the plane normal plastic strain ratio, which indicates the thinning resistance of the plate and the uniform ductility of the plate surface. The plastic strain ratio of the steel plate γ...

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Problems solved by technology

It can be seen that in recent years, the requirements for the formability of steel sheets have become increasingly stringent, and proposals to improve the processing performanc...

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