Preparation method of hot-dip galvanized sheet, and hot-dip galvanized sheet

Abstract

The invention discloses a preparation method of a hot-dip galvanized sheet and the hot-dip galvanized sheet. The preparation method is to prepare the cold-rolled steel strip into a hot-dip galvanized sheet through an annealing process and a hot-dip galvanizing process, including: querying the target annealing temperature of the annealing furnace used in the annealing process according to the parameters of the cold-rolled steel strip T0 and the target strip running speed U0; control the strip running speed U of the annealing furnace to meet U0-Ub≤U≤U0+Ua, and simultaneously control the annealing temperature T of the annealing furnace to satisfy T=T0, where 0m / min≤Ua≤10m / min, 0m / min≤Ub≤10m / min; adjust the strip running speed U, and when the strip running speed U is adjusted to U0-Uc≤U<U0-Ub, control The annealing temperature T=T0-Ta, wherein 10m / min≤Uc≤20m / min, 5°C≤Ta≤10°C. Compared with the existing technology, it eliminates the mixed crystal defects caused by the reduced speed production in the annealing process section, and at the same time avoids the deterioration of the mechanical properties of the steel plate caused by the lowered annealing temperature. It is simple and easy to implement, and the effect is remarkable.

Description

technical field [0001] The invention belongs to the technical field of production and manufacture of hot-dip galvanized steel sheets, in particular to a method for preparing a hot-dip galvanized sheet, and a hot-dip galvanized sheet prepared by the preparation method, in particular to a method capable of reducing mixing Method for preparing hot-dip galvanized sheet with crystal defects. Background technique [0002] Mixed grain defects refer to the existence of some obviously coarse grains (also known as coarse grains) in the structure of the steel plate, which leads to the deterioration of the uniformity of the structure. For the cold-rolled steel strip with mixed crystal defects, when the continuous hot-dip galvanizing line is further processed into a hot-dip galvanized sheet through cleaning, annealing, galvanizing, leveling and straightening, and post-treatment processes, it is easy to cause bright spots in the coating, stamping, etc. Quality problems such as orange pee...

AI Technical Summary

Problems solved by technology

[0007] However, in the actual production of cold-rolled steel strips processed into hot-dip galvanized sheets, it is inevitable to slow down production due to temporary equipment failures, making it extremely easy to produce unqualified products with mixed crystal defects during production, which affects product yield. cause cost increase

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