Preparation process of thin-gauge hot-dip galvanized steel plate and thin-gauge hot-dip galvanized steel plate

Abstract

The invention discloses a preparation process of a thin-gauge hot-dip galvanized steel plate and the thin-gauge hot-dip galvanized steel plate. According to the preparation process, surface cleaning, a tension deviation correction treatment procedure, a pre-heat treatment procedure, a hot-dip galvanizing procedure and a post-heat treatment process are conducted on a steel plate, the self-control pre-heat treatment procedure is conducted through a horizontal annealing furnace, and the post-heat treatment process is conducted through a cold spraying fan; the pre-heat treatment procedure comprises a 400-450 DEG C preheating section with the section outlet belt temperature of 400-450 DEG C, a 800-1100 DEG C direct combustion heating section with the section outlet belt temperature of 700-720 DEG C, a 800-850 DEG C radiant tube heat preservation section with the section outlet belt temperature of 700-720 DEG C and a 400-450 DEG C cooling section with the section outlet belt temperature of 400-450 DEG C; the temperature of zinc liquid in the hot-dip galvanizing procedure is higher than the section outlet belt temperature of the steel plate which passes through the cooling section; and the post-heat treatment process is used for ensuring that the belt temperature of the steel plate is lower than the solidifying point of zinc. According to the preparation process, hot wrinkle defects caused by the temperature difference between a heating annealing curve and a cooling curve can be obviously eliminated, the galvanizing protection effect is good, and the surface strength is high.

Description

technical field [0001] The invention relates to a preparation process of a hot-dip galvanized steel sheet, in particular to a preparation process of a thin-gauge hot-dip galvanized steel sheet, and also relates to a thin-gauge hot-dip galvanized steel sheet obtained by applying the preparation process. Background technique [0002] In recent years, with the rapid development of my country's home appliance manufacturing industry, the demand for galvanized home appliance panels is increasing rapidly, and the research technology of hot-dip galvanizing to thin gauge has also developed rapidly. The demand for galvanized sheets for home appliances is generally 0.3-0.8 mm. Among them, 0.5-0.8 mm galvanized sheet is generally used for high-strength washing machine panels, refrigerator panels and other parts; 0.3-0.5 mm galvanized sheet is generally used for refrigerator side panels and back panels that do not require high strength. However, in today's home appliance market, the pro...

AI Technical Summary

Problems solved by technology

However, when the 0.25 mm thick strip steel is hot-dip galvanized, it is very easy to cause longitudinal thermal wrinkles or even break the strip.

[0003] The applicant proposed the prior application CN110079647A, which mainly includes in-line annealing and hot-dip galvanizing process. The in-line annealing adopts the improved Sendzimir method annealing furnace, and mainly introduces the strip cooling curve in the cooling section to perform linear slow cooling. , so that the temperature of the cross-section of the strip is basically uniform, and solves the problem that thin-gauge strips are prone to thermal wrinkles; however, after the applicant’s method is applied in batches, it is found that it will still be affected by the temperature difference between the annealing curve and the cooling curve and cause heat The wrinkle problem will also lead to poor structural strength of the steel strip due to the thermal stress residual problem, and will also lead to poor adhesion of the subsequent hot-dip galvanizing