Cold rolling hot-dip steel with thickness greater than 1.5 mm for folding forming and production method thereof

Abstract

The invention relates to a cold rolling hot-dip steel with thickness greater than 1.5 mm for folding forming and a production method thereof, and mainly solves the technical problem that folding cracking of cold rolling hot-dip steel of thick specification can not be solved through annealing speed reduction or annealing temperature raising in the prior art. The method comprises the steps of: smelting according to components; carrying out molten iron desulphurization, converter top-bottom blowing, ladle bottom argon blowing or LF furnace refining, mild steel protection slag Ar blowing protective atmosphere pouring, slab heating furnace heating, de-scaling, rough rolling, finish rolling, post-segment control cooling and reeling to obtain a hot rolled strip; and then carrying out uncoiling, acid pickling, cold rolling, horizontal-chamber furnace continuous annealing, hot dipping and reeling to obtain a finished product. The continuous casting slab heating temperature is 1180-1220 DEG C; after rough rolling, an intermediate blank is rolled by a hot coil box, and uncoiled and sent into a first frame for finish rolling; rolling temperature of finish rolling is 1000-1040 DEG C, and the finishing temperature of finish rolling is 860-900 DEG C; the reeling temperature is 570-650 DEG C; the cold rolling reduction is 40-60%; the isothermal segment temperature for continuous annealing of cold-rolled strip steel in a hard state in the horizontal-chamber furnace is 720-770 DEG C; and the strip steel stays at the isothermal segment for 60-90 s. The product provided by the invention is mainly used in manufacture of industrial regulator cubicle casing and roof fillet of light steel building, etc.

Description

technical field [0001] The invention relates to a cold-rolled hot-dip galvanized steel and a manufacturing method thereof, in particular to a cold-rolled hot-dip galvanized steel for bending forming and a production method thereof. Background technique [0002] In the construction and industrial electrical industries, the use of thick-gauge cold-rolled hot-dip galvanized steel for bending and forming is increasing. For example, industrial electrical cabinet boxes, light steel building roof corrugated strips and other products are widely used in such materials. [0003] Compared with traditional hot-rolled steel sheets, sand-blasted steel sheets, and pickled steel sheets, cold-rolled hot-dip-coated steel sheets have good formability, high dimensional accuracy, and more uniform properties. With the improvement of social requirements for environmental protection and material economy, more companies in the construction and industrial electrical industries require the use of cold...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to meet the requirements of low-cost, batch, and stable production of thick-gauge cold-rolled hot-dip-coated steel products for bending and forming purposes, and to provide a thick-gauge cold-rolled hot-dip-coated steel with excellent bending forming performance and its manufacture The method is to solve the technical problem that the existing thick-gauge cold-rolled hot-dip galvanized steel is prone to bending and cracking during the bending forming process due to the composition design and the hot-rolling and cold-rolling process.

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