Hot-rolled high-strength sheet steel having tensile strength of 510MPa, and production method thereof

Abstract

The invention discloses a hot-rolled high-strength sheet steel having a tensile strength of 510MPa, and a production method thereof. The steel comprises 0.05-0.09wt% of C, 0.10-0.30wt% of Si, 0.70-1.50wt% of Mn, 0.025wt% or less of P, 0.012wt% or less of S, 0.015-0.040wt% of Ti, 0.01-0.03wt% of Als, and the balance Fe and inevitable impurities. The production method of the sheet steel comprises the following steps: desulfurizing molten iron, carrying out converter smelting, and alloying; carrying out ladle furnace treatment, and feeding Si-Ca wires during the treatment; carrying out continuous casting and rolling; tapping off the above obtained casted blank, and carrying out high pressure water dephosphorization; carrying out seven-stage rolling; carrying out laminar cooling; reeling; pickling; flattening; and finishing. The steel has stable performances, a high dimension precision and a good elongation rate, can be used in automobile structure and safety members comprising passenger car chassis, various reinforcing plates and the like, and reduces the automobile production cost, and the production method of the steel has a low production cost and good industrial production adaptability.

Description

Technical field [0001] The invention belongs to the technical field of automobile steel, and specifically refers to a hot-rolled high-strength thin steel plate with a tensile strength of 510MPa and a production method. Background technique [0002] With the development of automobile lightweight technology, the thinning of automobile structure and high-strength steel for safety is the most direct way of automobile lightweight. At present, thin (≤2.0mm) steel sheets commonly used in automobile production are mainly used in the production of automobile chassis systems, body structure systems, seat safety systems and other parts. [0003] Compared with traditional hot-rolling production lines, the hot-rolled steel sheet produced by the thin slab continuous casting and rolling (CSP) method has the characteristics of short process flow, high strength, low cost, especially thin thickness specifications, and is an effective means for lightweighting cars . Taking advantage of the advantag...

AI Technical Summary

Problems solved by technology

However, the high-strength steel produced by the above-mentioned advanced steel mills at home and abroad by the CSP method has achieved certain technical effects, but in order to pursue the comprehensive performance of steel products, they have added more alloying elements to the steel, resulting in an increase in the cost of the steel , and the thickness of the steel they produce is higher than 2.0mm, and the thickness of the product needs to be further improved

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