Continuous-casting dynamic soft-reduction pressing quantity on-line control method of large square blank

Abstract

The invention relates to a continuous-casting dynamic soft-reduction pressing quantity on-line control method of a large square blank, in particular to a continuous-casting dynamic soft-reduction process of the large square blank in iron and steel production; the method is as follows: casting blank surface pressing quantity of all pressing points is calculated in an on-line way according to basicprinciples that center segregation and porosity can be eliminated by solidifying contraction of a soft-reduction pressing quantity compensating liquid core, so as to determine the roll gap setting value of racks of all tension levelers; the roll gap setting value is transmitted to a one-level basic automation control system, so as to adjust the roll gap of the tension leveler remotely and realizesoft reduction. After adopting the invention, the special indexes for improving the quality of a casting piece are that: the center segregation of the casting blank is less than or equal to 1.0 grade,center carbon segregation index of the casting blank is 0.95-1.10, and the average is 1.05; center porosity and center line shrinkage of the steel casting blank of a bearing can be obviously improved, the center porosity of the casting blank is less than or equal to 1.0 grade, the proportion thereof can reach more than 90 percent, and the center line shrinkage is less than or equal to 0.5 grade;by adopting the invention, the disadvantages of center segregation, center porosity and center line shrinkage of the large square blank can be remarkably alleviated.

Description

technical field [0001] The invention relates to a bloom continuous casting soft reduction process in steel production, in particular to an online control method for bloom continuous casting dynamic soft reduction reduction. Background technique [0002] During the continuous casting production process, the slab is continuously solidified from the outside to the inside under the action of external cooling, and the resulting solidification shrinkage is supplemented by the free molten steel that can flow in the center. With the increase of flow resistance in the phase area, the solidification shrinkage cannot be compensated in time, and the resulting pressure drop will cause the enriched segregation element molten steel between the dendrites near the center of the slab to flow to the center, gather and finally solidify, thus forming central macro segregation , At the same time, the uncompensated solidification shrinkage will eventually form the central porosity. [0003] Inter...

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Problems solved by technology

These methods all set the amount of light reduction in advance, and it is difficult to effectively improve th

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