Method for producing hot-rolled pickling-free plate by combining thin-strip continuous casting with reducing annealing

Abstract

The invention belongs to the technical field of material metallurgy, and particularly relates to a method for producing a hot-rolled pickling-free plate by combining thin-strip continuous casting with reducing annealing. The method specifically includes the steps: obtaining refining molten steel, preparing a cast-rolling strip blank, uncoiling a cast-rolling thin strip after thermal leveling for reducing annealing, removing scale on the surface of the cast-rolling thin strip in a reduction section, and adopting H2 atmosphere condition to protect reduction, wherein reduction temperature is 800-1100 DEG C and reduction time is 10-30min; adopting H2 and N2 atmosphere for protection in a high-temperature annealing section, wherein reduction temperature is 500-1000 DEG C and reduction time is 1-5min, realizing texture and performance control of the thin strip, and obtaining a thin-strip steel product. By the technical scheme, the cast-rolling thin strip is free of pickling and is directly subjected to reducing annealing, so that cold-rolled pickling process is omitted, pre-oxidation process before continuous annealing can be completely abolished, continuity of thin strip production process can be greatly improved, production efficiency is improved, production cost is lowered, discharging of pollutants like waste acid is reduced, and great economic benefit and social benefit are created.

Description

technical field [0001] The invention belongs to the technical field of material metallurgy, and in particular relates to a method for producing hot-rolled pickling-free plates combined with strip continuous casting and reduction annealing. Background technique [0002] In recent decades, the iron and steel industry at home and abroad has been developing new technologies around saving energy, improving production efficiency, and improving product quality, so as to achieve the goal of long-term and continuous energy saving and quality improvement. Thin strip continuous casting technology, as a near-net-shape casting technology that can directly cast the shape, size and quality of the final product as close as possible, is an important new technology with the greatest potential in the field of continuous casting, but for the iron oxide scale produced in the continuous casting process The removal of waste acid has always been a recognized problem, and it is usually removed by p...

AI Technical Summary

Problems solved by technology

Danieli in Italy uses reduction annealing furnace to directly reduce hot-rolled strip steel, and the surface quality of strip steel obtained is even better than that of pickled steel plate. However, the above two production schemes are mainly for the traditional hot-rolled production process. The production process of the traditional hot rolling production line is long and there is no inert gas protection. The thickness of the iron oxide scale on the surface of the strip is thicker, which increases the difficulty of the subsequent scale reduction stage. The reduced iron scale is mostly removed mechanically, and the production efficiency is low.

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