Method for improving self-feeding capacity of high and thick large-cross section casting blank

Abstract

The invention relates to the field of casting blank manufacturing, in particular to a method for improving the self-feeding capacity of a high and thick large-cross section casting blank, and can solve the problems that the center quality of the thick large-cross section casting blank is poor, cracks are generated on the surface of the thick large-cross section casting blank, and the rejection rate is high in the prior art. The method comprises the following steps of: controlling external cooling conditions of different solidification stages of the casting blank to quickly solidify the outer surface of the casting blank to form a shell, establish strength and prevent surface cracks from being generated; performing heat preservation and slow cooling on the surface of the casting blank to keep a large area of a core part in a pasty area, wherein a solidification layer on the outer surface of the casting blank is kept at a higher temperature so that plastic deformation is realized; and performing simultaneous solidification and solid-phase movement in the subsequent solidifying and shrinking process of the casting blank to fulfill the aim of radial self-feeding of a deformable metal at a high temperature so as to eliminate the internal shrinkage cavities and surface cracks of the casting blank and obviously improve the looseness until the internal looseness of the casting blank is eliminated. The method is applicable to the high and thick large-cross section casting blank, particularly to a thick large-cross section casting round blank and a thick large-cross section casting square blank of which the height-diameter ratio is high and the axial looseness cannot be improved through riser feeding.

Description

technical field [0001] The invention relates to the fields of metal mold casting wide and thick slabs, continuous casting round billets with thick and large sections, square billets and rectangular billets, etc. The method of shrinkage porosity and surface cracks inside the billet. Background technique [0002] Wide and thick plates are widely used in my country's economic construction. Wide and thick plates are widely used in large ships, ocean-going platforms, hydropower units, thermal power units, pressure vessels, mold manufacturing and long-distance pipelines. my country has recently built dozens of wide and heavy plate rolling production lines, including Anshan Iron and Steel's 5000mm and 5500mm rolling mills, Baosteel's 5000mm rolling mills, etc., with a new capacity of more than 20 million tons. Therefore, there is a huge demand for wide and thick slabs with thick and large sections for rolling wide and thick plates. At present, the maximum thickness of continuous...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a method for improving the shrinkage cavity and surface cracks in the center of the thick and large section die-casting wide and thick slab, continuous casting round billet and rectangular billet by improving the self-feeding ability of the thick and large section billet, and solving the existing problems. In technology, the quality of the billet center is poor, cracks appear on the surface, and the scrap rate is high.

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