High-speed stable production method of CQ-grade thin-gauge galvanized sheet

Abstract

The invention relates to a high-speed stable production method of a CQ-grade thin-gauge galvanized sheet. According to the method, a continuous hot galvanizing unit sink roll preheating model, the purity of zinc liquid, a plan schedule, secondary crescent shearing, the temperature of an annealing furnace, a sink roll scraper and the tension of a zinc pot are comprehensively controlled, the average running speed of a CQ-grade thin-specification galvanized sheet is improved from 90m / min to 140m / min, the capacity is fully released, and the production efficiency is improved; the in-furnace wrinkle judgment change rate is reduced from 8.11% to below 1%, the scratch and wrinkle degradation judgment change rate is greatly reduced, and the cost is reduced; and the yield is greatly improved, cost reduction and efficiency increase are obvious, order delivery is effectively guaranteed, the productivity is greatly released, and the method can be applied to a continuous hot galvanizing production line.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a high-speed and stable production method for CQ grade thin-gauge galvanized sheets. Background technique [0002] When the continuous hot-dip galvanizing unit in a steel plant produces CQ-grade thin-gauge galvanized sheets, the general speed is 70-90m / min, the production capacity is low, and the order delivery cannot be effectively guaranteed; sometimes the speed can reach 110m / min, but once the specification There will be scratches on the surface of the steel strip before plating, and there will be collisions when the crescent of the weld is out of the zinc pot, and there will be folds at the head and tail of each roll, and even continuous large-area folds in the strip, which seriously restricts Production line production will increase the rate of change of judgment of the unit and reduce the rate of finished products and even the risk of belt breakage. The surv...

AI Technical Summary

Problems solved by technology

[0003] Stable production of thin gauges has always been a problem in the production of continuous hot-dip galvanizing units. There are two conventional technologies for producing thin gauges. One is to avoid scratches on the surface of wrinkled steel strips in the strip furnace at high speeds and product degradation; the other is to avoid scratches at low speeds. Injury, but the production capacity is low, there are wrinkles when the weld seam leaves the annealing furnace, and the product surface is poor at low speed, which cannot meet the needs of high-end home appliance boards

[0004] The existing public technology controls the roughness of the sinking roll at 3-5um under the traditional production process of CQ grade thin-gauge galvanized sheet, and the roughness attenuation of the sinking roll is serious in the middle and later stages, which is not suitable for high-speed production of thin-gauge galvanized sheet, for example, Publication No. Patent CN201911030742 A method for preventing surface scratches of ultra-thin hot-dip galvanized sheets

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