Rolling method for optimizing the surface quality of hot-rolled steel sheets

Abstract

The invention discloses a rolling method for optimizing the surface quality of a hot rolled steel plate, comprising phosphorus removal before continuous casting roughing and roughing control, wherein the total deformation of roughing is 70-85%, and rolling reduction of each pass in roughing control is in progressive increase. By taking the steel surface quality as the factor of influencing load distribution, a load distribution method in which the rolling reduction of each pass in roughing control is in progressive increase is adopted, so that oxide scale thickness is effectively reduced, possibilities of oxide scale press-in and red ironhide can be reduced, the surface quality of a hot rolled steel plate is improved, and steel plate components, tissue uniformity and mechanical property can be ensured while the oxide scale thickness is reduced. According to the method, the rolling power of a rolling mill can be fully utilized on the premise of not influencing the yield of energy consumption, and the method can be widely used in production of hot rolled steel plates. According to the method, additional facility and input are not increased, the investment is low, rapid effect is achieved and the operation is convenient.

Description

Technical field [0001] The invention relates to a steel rolling process control technology, in particular to a rolling method for optimizing the surface quality of a hot rolled steel sheet. Background technique [0002] With the development of modern industry, users have higher and higher requirements for the surface quality of steel products. Surface quality defects such as red rust and iron sheet pressing often appear on the surface of hot-rolled products, which seriously hinder the improvement of steel product quality. [0003] After the hot-rolled slab comes out of the heating furnace, it is rough-rolled after descaling by high-pressure water and other methods. During the rough-rolling process, secondary oxide scale is produced on the surface of the steel plate. The secondary oxide scale has good high-temperature plasticity and is together with the steel plate during rough rolling. Deformation and poor peelability. If the secondary scale cannot be completely removed by sprayin...

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Problems solved by technology

[0004] In the past, pickling, cold rolling, hot-dip galvanizing or coating have been used for surface treatment. In recent years, the introduction of energy-saving and emission-reduction guidelines has prompted downstream industries to meet increasingly stringent environmental protection requirements. Pickling and derusting processes are restricted, regardless of The production cost of pickling or plating process is relatively high; in addition, due to the limitation of rolling capacity of rolling equipment, the distribution of reduction in traditional roughing mills is generally high temperature and large reduction, and the first consideration is bite capacity and thickness. fluctuate, the reduction is slightly smaller, and the absolute value of the second reduction is the largest, and then the reduction decreases step by step to make full use of the high-temperature plasticity of the steel, so that the slab can be expanded at a high temperature where the oxide scale formation rate is relatively fast. In recent years, my country's steel rolling technology has advanced by leaps and bounds, and the rolling capacity of rolling equipment has been greatly improved, but the above-mentioned reduction distribution method when the rolling mill capacity is weak is still in use today.

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