A method for removing oxides on the strip surface of carbon steel

Abstract

The invention relates to a method for eliminating oxide on the surface of band steel of carbon steel. The oxide on the surface of the band steel includes Fe2O3, Fe3O4 and FeO. The method comprises the following specific steps: uncoiling the band steel by an uncoiling machine; crushing and stripping the oxide on the surface of the band steel by a leveling machine; further crushing and stripping the oxide on the surface of the band steel by a multi-roll straightening machine; pickling the leveled and straightened band steel; and coiling the processed band steel to obtain a finished product by a coiling machine. Through the technical scheme, the method has the beneficial effects that a plurality of oxide cracks exist on the surface of the processed band steel, and the gaps of the oxide cracks are large, so that acid liquid in the acid pickling process can rapidly permeate into the band steel, and the acid pickling efficiency can be remarkably improved; the yield strength of the processed band steel is hardly increased, so that the performance of the band steel is basically not influenced; the yield platform of the band steel can be eliminated through the leveling process, and LUDERS which is frequently formed on an ordinary hot-rolled product can be prevented; the thickness precision and strip shape precision of the band steel can be improved.

Description

technical field [0001] The invention relates to a common hot-rolled flat material deep processing technology, in particular to a strip surface oxide removal method for carbon steel. Background technique [0002] In the existing technology, such as figure 1 As shown, the traditional pickling unit consists of an uncoiler 1, an inlet looper 2, a tension leveler 3, pickling 4, a rinse 30, an exit looper 5, and a coiler 6, and the tension leveler 3 is used for mechanical scale breaking , form oxide cracks 9 on the surface oxide 8 of the strip steel 7 to improve pickling efficiency, but this method of descaling has many problems such as unsatisfactory descaling effect and great damage to product performance. [0003] like figure 2 As shown, oxides 8 on the surface of the strip steel 7 form oxide cracks 9 consistent with the width direction of the strip steel 7 under the action of tensile stress and bending stress during the tension leveling process, and the strip steel 7 after ...

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Problems solved by technology

[0004] Therefore, in the process of pickling 4, it is difficult for the acid solution in the pickling tank to penetrate into the FeO layer from the closed oxide crack 9 and react with it, thus causing the efficiency of pickling 4 to be very low. For pickling efficiency, it is necessary to set the elongation of the tension leveler 3 above the yield limit of the strip steel 7, so that the strip steel 7 produces plastic deformation. In this working condition, the strip steel 7 can be Partially maintain the gaps of surface oxide 8 to improve pickling efficiency, but the performance loss of strip steel 7 products is serious

[0005] like image 3 As shown, for conventional hot-rolled sheets with carbon, nitrogen and other interstitial atoms content ≥ 30ppm, uneven surface yield will occur on the surface of strip steel 7 after entering the tension leveler 3, commonly known as Lüders strip 10; for high-strength steel, IF steel Although the produced steel strip 7 will not produce Lüders strip 10 on the surface of the strip steel 7, since its yield strength increases unidirectionally with the increase of the elongation, increasing the elongation will undoubtedly deteriorate the product performance

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