Production method for Si-contained cold-rolling hot galvanizing dual-phase steel with tensile strength reaching 800MPa level

Abstract

The invention relates to a production method for Si-contained cold-rolling hot galvanizing dual-phase steel with tensile strength reaching 800MPa level. The cold-rolling hot galvanizing dual-phase steel comprises, by mass, 0.08%-0.12% of C, 0.10%-0.18% of Si, 1.5%-2.5% of Mn, 0.2%-0.4% of Cr, 0.12%-0.20% of Mo, 0.03%-0.06% of Als, 0-0.015% of P, 0-0.04% of S, 0-0.005% of N, and the balance Fe and inevitable impurities. Due to the fact that chemical component design is combined with cold rolling, hot rolling, continuous annealing and hot galvanizing technical control, stable production of steel plates can be guaranteed. According to the steel produced through the method, yield strength is 426MPa-540MPa, tensile strength is larger than or equal to 800MPa, and the ductility is larger than or equal to 15%. The production method has the characteristics that cost is low, equipment is simple and product application performance is good.

Description

technical field [0001] The invention relates to the field of manufacturing cold-rolled hot-dip galvanized steel for automobiles, in particular to a production method of cold-rolled hot-dip galvanized dual-phase steel containing Si with a tensile strength of 800 MPa. Background technique [0002] With the development of the automobile industry, saving energy and reducing consumption, increasing safety and reliability, and improving the corrosion resistance of the car body have become common pursuits of users. The use of high-strength galvanized sheets has become an inevitable trend in the development of automotive steel. [0003] Dual-phase steel is currently the most widely used high-strength steel in the automotive industry. Dual-phase steel for automobiles is divided into hot-rolled dual-phase steel, cold-rolled dual-phase steel, and cold-rolled hot-dip galvanized dual-phase steel according to different process paths. Among them, the dual-phase steel with The ferrite / marte...

AI Technical Summary

Problems solved by technology

[0012] That is to say, there are the following problems in the prior art: galvanized dual-phase steel not only has high strength, low yield ratio and good formability of cold-rolled dual-phase steel, but also has good anti-corrosion performance. Phase steel has been widely used in door anti-collision beams, seat brackets, floor plate beams and other safety and structural parts

This virtually increases the cost, and at the same time, the addition of various alloying elements also puts forward higher requirements for process control

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