Preparation method for 800 MPa low-temperature resistant high strength steel

Abstract

The invention discloses a preparation method for 800 MPa low-temperature resistant high strength steel. The method comprises the steps of heating, descaling, rough rolling, finish rolling and pre-straightening of a plate blank obtained through continuous casting; the plate blank comprises the following chemical components, by mass: 0.08%-0.12% of C, 1.1%-1.4% of Mn, 0.02%-0.04% of Nb, 0.01%-0.03%of Ti, 0.2%-0.5% of Cr, 0.1%-0.3% of Mo and 0.0015%-0.003% of B; in the pre-straightening process, the bite speed is 0.5-0.8 m/s; and a steel plate is water-cooled, air-cooled and tempered on line toobtain the low-temperature resistant high strength steel. According to the preparation method, the hot rolled steel plate is directly subjected to quenching treatment, and reheating after cooling is not required; the waste heat utilization of the steel plate is achieved, and energy sources are saved; and the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of steel rolling, and in particular relates to a preparation method of 800MPa low-temperature-resistant high-strength steel. Background technique [0002] Low-temperature-resistant high-strength steel belongs to high-strength welded structural steel, with a thickness of 8-120mm in general, and can be widely used in coal mining machinery, construction machinery and other fields. In order to ensure the strength of the product, this low-temperature-resistant high-strength steel is generally delivered in a quenched and tempered state. Its conventional production process is that the slab obtained by continuous casting is heated by a heating furnace-dephosphorization-rolling-steel plate cooling-steel plate offline quenching-steel plate tempering, this conventional production process is due to production line equipment and layout, etc. After the steel plate rolling process is completed, it is naturally cooled off ...

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Problems solved by technology

[0003] Aiming at the deficiencies of the above-mentioned prior art, the present invention provides a preparation method of 800MPa low-temperature-resistant high-str

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