A method for producing hot-rolled pickling-free plates by strip continuous casting combined with reduction annealing

Abstract

The invention belongs to the technical field of material metallurgy, and specifically relates to a method of thin strip continuous casting combined with reduction annealing to produce hot-rolled pickling-free plates. The specific steps are to first obtain refined molten steel, prepare cast-rolled strip, perform hot leveling, and then uncoil the cast-rolled strip for reduction annealing. In the reduction section, first remove the iron oxide scale on the surface of the cast-rolled strip, and use H2 atmosphere conditions to protect the reduction. The reduction temperature is 800-1100°C, and the reduction time is 10-30 minutes; H2 and N2 atmosphere protection is used in the high-temperature annealing section, the reduction temperature is 500-1000°C, and the reduction time is 1-5 minutes to achieve control of the structure and performance of the thin strip and obtain a thin strip. Strip steel products. The technical solution of the present invention directly reduces the annealing of the cast-rolled thin strip without pickling, eliminating the cold-rolling pickling process. At the same time, the pre-oxidation process before continuous retreat can be completely eliminated, which will greatly improve the continuity of the thin strip production process. While improving production efficiency, it also reduces production costs and reduces waste acid and other pollutant emissions, producing huge economic and social benefits.

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 b...

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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