Low-compression-ratio method for producing heavy-gauge flaw-detection-maintaining steel plate

Abstract

The invention discloses a low-compression-ratio method for producing a heavy-gauge flaw-detection-maintaining steel plate. According to the method, a steel plate which meets the requirement of GB first-grade flaw detection and fulfill each performance index of steel plates can be obtained by innovations on clean steel production, continuous casting, heating, rolling and normalizing processes, wherein a dynamic soft reduction technology is adopted in the continuously casting process, casting production of a slab with thickness of 2500mm can be protected in the whole journey by means of low-temperature slow-pulling-rate, the center segregation of the slab is required to be less than 1.5 of C model; the slab heating temperature is controlled to be 1050-1220 DEG C, the temperature of the descaled slab is controlled to be 1000-1100 DEG C. A high-temperature, non-controlled rolling and high reduction process is adopted as the rolling principle, maximal capacity of a rolling mill is adopted in the deforming process to guarantee the pass reduction rate, so that the deformation can infiltrate into the center of a steel plate; and the last pass is performed when the lower limit of the deformation temperature range is met, and the reduction rate and the deformation temperature are effectively combined, so that the reduction rate is more than or equal to 20 percent.

Description

Technical field [0001] The invention relates to a method for producing thick-gauge flaw detection steel plates with a low compression ratio, and belongs to the technical field of metallurgy. Background technique [0002] In recent years, with the rapid development of heavy machinery and wind power industries, the use of steel plates with a thickness of 80 to 120 mm has increased month by month. At present, many domestic steel companies use continuous casting machines for casting billet rolling. The thickness of the cast billet is generally less than 250mm. To ensure the internal quality of the steel plate, the reduction ratio of the rolling process is required to be ≥4, which makes it impossible to receive orders for 80-120mm steel plates. Because in the production of 80-120mm thick steel plates, especially steel plates with flaw detection requirements, if a lower compression ratio is used under the current process conditions, the original looseness of the core of the cast slab w...

AI Technical Summary

Problems solved by technology

At present, many domestic iron and steel enterprises use continuous casting machines to roll casting slabs for the production of steel plates. The thickness of the casting slabs is generally less than 250mm. In order to ensure the internal quality of the steel plates, the compression ratio of the rolling process is required to be ≥ 4, resulting in the inability to accept orders for steel plates of 80-120mm.

Because in the production of 80-120mm thick steel plates, especially when producing steel plates with flaw detection requirements, if a lower compression ratio is used under the current process conditions, the original loose defects in the core of the slab will occur, which cannot be pressed together, and eventually Resulting in unqualified steel plate flaw detection

[0003] In order to realize the production of thick-gauge steel plates, some enterprises have developed a composite billet-making process. However, due to the low production efficiency of this process, it is difficult to meet the requirements of the composite surface. The production and processing cost is 500 yuan / ton higher than that of billet direct rolling, and the production cycle is long. Restricted by other factors, the actual output is very low

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