Method for removing oxides from surface of strip carbon steel with low acid consumption

Abstract

The invention relates to a method for removing oxides from the surface of strip carbon steel with low acid consumption. Oxides on the surface of strip carbon steel comprise Fe2O3, Fe3O4 and FeO, and the method comprises the following steps: uncoiling by an uncoiling machine; crushing and peeling off oxides on the surface of a strip steel by a flattening machine; further crushing and peeling off oxides on the surface of a strip steel by a multiroll flattener; removing falling-off and loose oxides from the surface of the strip steel by a scrubbing roller in a scrubbing device; carrying out acid pickling and rinsing to the strip steel which is subjected to flattening, straightening and scrubbing treatment; and coiling the treated strip steel by a coiling machine to obtain a finished product. With the adoption of the technical scheme, the method has the beneficial effects that more cracks of oxides on the surface of the treated strip steel are formed, the gaps are large, acid liquid can rapidly permeate conveniently during acid pickling, and the acid pickling efficiency is improved; the scrubbing device can further remove unpeeled-off oxides which are separated from a strip steel machine body, so as to prevent the unpeeled-off oxides which are separated from the strip steel machine body from entering acid pickling procedure, acid reaction dose is increased, and acid consumption and the production cost are reduced.

Description

technical field [0001] The invention relates to the technical field of deep processing of ordinary hot-rolled flat materials, in particular to a method for removing oxides on the strip surface of low-acid carbon-consuming 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 phosphorus removal. , forming oxide cracks 9 on the surface oxide 8 of the strip steel 7, but this phosphorus breaking method has many problems such as unsatisfactory phosphorus breaking effect and great damage to product performance, and the tension leveler 3 can only be used on the strip steel 7 Oxide cracks 9 are formed on the surface oxides 8, and part of the oxides 8 on the surface of the strip steel 7 cannot be removed. All oxides 8 need to be removed by pickl...

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Problems solved by technology

[0004] Therefore, in the process of pickling 4, the acid solution in the pickling tank is difficult to penetrate into FeO33 from the closed oxide crack 9, and react with it, thus causing the efficiency of pickling 4 to be very low. In order to improve the cleaning 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. Under this working condition, the strip steel 7 can be partially Maintain the gaps of surface oxide 8 and improve pickling efficiency, but the performance loss of strip 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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