Non-steady state continuous casting process capable of damaging small steel ingot structure

Abstract

The invention discloses a non-steady state continuous casting process capable of damaging a small steel ingot structure, and belongs to the technical field of metal material preparation. A drawing velocity is based on the conventional drawing velocity Vo, and is vertically fluctuated at small amplitude in a certain period T, namely V=Vo+a; and after continuous casting is started normally and becomes stable, a certain conventional drawing velocity Vo is determined according to a superheat degree, the drawing velocity is improved to Vo+a, billets are continuously drawn for time of T1, the drawing velocity is reduced to Vo-a in time of T3, the billets are continuously drawn for time of T2, and the drawing velocity is improved to Vo+a in time of T4 to complete a billet drawing period T. The non-steady state continuous casting process has the advantages that: the small steel ingot structure can be damaged and dendrite is inhibited from bridging, so that the compactness of continuous castings is improved, a non-steady state continuous casting process with center segregation is improved, and the non-steady state continuous casting process is suitable for continuous casting production lines for square billets, plate billets, round billets and the like.

Description

technical field [0001] The invention belongs to the technical field of metal material preparation, and in particular relates to an unsteady continuous casting process capable of destroying the structure of small steel ingots, which is suitable for continuous casting of small square billets and thick slabs. Background technique [0002] The internal quality of the continuous casting slab mainly involves internal defects such as the central porosity of the continuous casting slab (shrinkage cavity in severe cases), central segregation, V-shaped segregation, and central cracks. For high-carbon wire rods, the looseness and segregation in the center will reduce the drawability and increase the breaking rate; the thickest slab in China is 420mm thick, and the largest round billet diameter is 900mm, and the internal quality, especially the looseness and segregation, is getting worse. important. [0003] The basic principle that affects the internal quality of continuous casting sl...

AI Technical Summary

Problems solved by technology

These research results all show that the solidification end is dynamic, and the casting speed has a relatively important influence on the length of the liquid core, so try to pursue steady pouring in production, and pursue the stability of the solidification end. So far, no one has imagined using unsteady pouring ( The fluctuation of the casting speed) to destroy the structure of the small steel ingot, so that the internal quality of the continuous casting slab can be improved

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