A kind of hpb300 steel material and the production method for improving the surface scarring of hpb300 steel material

Abstract

The invention discloses a HPB300 steel product and a production method for improving the scarring on the surface of the HPB300 steel product. The production method includes the steps of converter smelting, continuous casting, rolling, cooling in a water tank and coil collection to obtain coiled HPB300 steel products. Before converter smelting For hot metal desulfurization pretreatment, use fluorite as desulfurizer, add 60kg fluorite per 120t of molten steel to desulfurize molten steel; during converter smelting, add SiCaBa and SiAlBa when the converter is tapping one-third to two-thirds of the steel. For deoxidation, the tapping temperature is controlled at 1650-1660°C; during continuous casting, the upper temperature limit of the continuous casting furnace of the casting machine is 1555 to 1565°C, the water distribution of the mold in the first zone is set to 7t / h, and the water distribution in the second zone is set to 6t / h ; when the water-cooled tank is cooling, the pressure of the forward purge water tank is controlled at 1.5MPa, the temperature is controlled between 880-900°C, and the pressure of the reverse purge water tank is controlled at 2MPa; and a kind of HPB300 steel; It can effectively reduce the intermediate cracks caused by the cracking of columnar crystals, and achieve the effect of improving the quality of steel and making it more economical and convenient.

Description

technical field [0001] The invention relates to a steel product, in particular to a HPB300 steel product and a production method for improving the scarring on the surface of the HPB300 steel product. Background technique [0002] At present, the production process of hot-rolled smooth round steel bar HPB300 is mainly completed through ironmaking-steelmaking-continuous casting-rolling-controlled cooling-coil collection-packing. Among them, the Si content of HPB300 steel is about 0.50%, the S content is about 0.40%, and the secondary cooling water distribution of 8.0 tons / hour is used to produce the HPB300 steel grade with 5 machines and 5 strands of high-speed continuous casting machine. There are many defects. The internal defects of the slab cannot be eliminated during the rolling process, and in the stage of controlled cooling after rolling, improper control of the back-blowing water pressure will aggravate the formation of surface scarring, resulting in poor surface qual...

AI Technical Summary

Problems solved by technology

These defects cannot be completely eliminated during the rolling process. In addition, the spinning temperature is too high, and the defects will be further enlarged when the water tank is blown back, which will have a great impact on the surface quality of the steel.

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