Continuous production method for temporary protective layer of hot-rolled strip steel and hot-rolled strip steel

Abstract

The invention relates to a continuous production method for a temporary protective layer of hot-rolled strip steel and the hot-rolled strip steel. The method sequentially comprises the following steps: uncoiling and straightening: welding and connecting the head part of the strip steel to be treated and the tail part of the front coil of strip steel, opening the strip steel to be treated, and then feeding the strip steel into a straightening machine for straightening; surface cleaning: cleaning floating ash and oxide particles on the surface of the straightened strip steel; surface treatment: firstly confirming that the surface of the strip steel meets the treatment requirement, and then carrying out continuous surface treatment on the strip steel to form a temporary protective layer on the surface of the strip steel; surface detection: carrying out online detection on the surface of the strip steel, wherein the online detection comprises detection on the curing degree, the thickness, the coverage rate and pinholes of a temporary protective layer; .and trimming and packaging: trimming the strip steel with the temporary protective layer, and performing cutting, packaging and warehousing according to delivery form requirements The hot-rolled strip steel comprises the temporary protective layer, and the temporary protective layer is obtained through the continuous production method of the temporary protective layer of the hot-rolled strip steel.

Description

technical field [0001] The invention relates to a protective coating for hot-rolled strip steel, in particular to a continuous production method for a temporary protective layer of hot-rolled strip steel and the hot-rolled strip steel. Background technique [0002] Hot rolling is one of the important production and processing procedures in steel production. Its purpose is to change the thickness of the heated billet, control its width or inner and outer diameters, and extend its length through discontinuous or continuous rolling processes. At the same time, the rolling process and cooling control give The required mechanical properties of steel. Hot rolling is a high-temperature process, and the surface of the steel is continuously oxidized to form an oxide scale. This layer of black oxide scale with a thickness of several microns to tens of microns can provide protection for the hot-rolled steel during production, storage and transportation, and can slow down product corros...

AI Technical Summary

Problems solved by technology

However, these adjustments often inevitably affect the on-site production rhythm, product organization and mechanical properties, etc., and the improvement in oxide scale protection performance is limited, which may not necessarily meet user needs

Another method is to improve the corrosion resistance of steel through some protective means, such as the most conventional anti-rust paper packaging, but this method must ensure that the anti-rust paper does not break the packaging, which puts higher requirements on product production and inventory management, and also It cannot solve the problem of oxide skin falling off and polluting the site; another example, anti-rust oil is also a relatively common method, which can reduce oxide skin dust falling off to a certain extent, but anti-rust oil will have a serious impact on product welding and coating. It needs to be removed by degreasing, which increases the cost of use. Similarly, other conventional coating products also have similar problems

[0005] Moreover, the existing technical solutions for the temporary protection of hot-rolled steel are mainly aimed at the protection of high-temperature oxidation and burning loss in the hot-rolled production process. For example, Chinese patent 200610076257.0 discloses a high-temperature ordinary low-carbon steel anti-oxidation coating and its application. Chinese patent 201510252212.3 discloses a protective coating for steel slabs in hot-rolled heating furnaces. None of the above-mentioned disclosed patents can solve the problems of black ash and easy corrosion of steel after hot-rolled coiling

[0006] Although conventional anti-corrosion coatings can better solve the above-mentioned problems of hot-rolled steel, these technologies are not aimed at the protection of hot-rolled steel during production, storage and transportation, but the protection of hot-rolled steel during service.

Therefore, most of these technologies require complex processes. In order to ensure the coating performance, it is often necessary to remove the black scale on the surface by means of pickling or shot blasting. Multiple coatings such as primers and topcoats are required, which takes a long time. The coating is solidified to form a film, not suitable for continuous production of hot-rolled steel

In addition, these technologies are excessive protection for the protection requirements of hot-rolled steel during production, storage and transportation. During use, it will cause a series of problems such as steel welding, forming, and coating. Repair, but increase the cost of use

Chinese patent 200810088982.9 discloses a method for continuously producing antirust primer-coated steel sheets. This method continuously coats the primer coating on the surface of hot-rolled strip steel, reduces intermediate links, and can provide hot-rolled strip steel during production, storage and transportation. Temporary protection during the process, but this method has complicated procedures, not only needs to pickle the hot-rolled sheet to remove scale, which is easy to pollute the environment, but also requires high-temperature baking and curing for the coating primer, resulting in high energy consumption and increased equipment investment cost, the formed primer coating will have adverse effects on the subsequent welding, forming and other user links. The welding part must be polished to remove the primer coating before welding, and then the primer needs to be reapplied. Damaged parts of the coating during transportation must also be repainted after sanding to remove the primer

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