Continuous casting alloy steel bloom convex combined roller and heavy pressing process

Abstract

The invention discloses a continuous casting alloy steel bloom convex combined roller and a heavy pressing process. The core quality problem of a continuous cast bloom is solved. The technical schemecomprises the convex combined roller and the heavy pressing process; the convex combined roller is characterized in that a pulling-straightening roller is designed to be a constant-curvature boss-freeconvex roller body capable of improving the segregation in the flowing direction of enriched molten steel before the continuous cast bloom is solidified and a gradually-changed-curvature boss convexroller body capable of compensating severe looseness and cavity shrinkage defects formed by volume shrinkage; the constant-curvature boss-free convex roller body is located at the position where the central solid phase ratio is 0.2; the gradually-changed-curvature boss convex roller body is located at the position of the solidification ending point; the accurate pressing parameters of the convex roller bodies are determined; and pressing under large deflection is conducted in sequence at the two positions. The continuous casting alloy steel bloom convex combined roller and the heavy pressing process have the beneficial effects that by adoption of the convex combined roller equipment and the heavy pressing process, the quality defects of the segregation of chemical components, solidification center cavity shrinkage and severe looseness of the continuous cast bloom are overcome, and the macroscopic examination shows that the core quality of the continuous cast bloom is remarkably improved and quality is stable.

Description

technical field [0001] The invention relates to a continuous casting alloy steel bloom convex combination roll and a heavy reduction process, belonging to the field of continuous casting of steel production. Background technique [0002] In order to eliminate quality problems such as center porosity, center segregation, and shrinkage cavity of the continuous casting slab, domestic alloy steel bloom continuous casting machines have basically introduced foreign straight roll multi-stand and dynamic soft reduction equipment technology. Due to the larger cross-section of the bloom, the temperature of the shells on both sides is about 20°C lower than that of the center, and the tensile strength is higher, so the deformation resistance is greater, and the shells on both sides have a greater lateral tensile force on the liquid core, which easily leads to the formation of solid-liquid interface For tearing, only the technology of multi-pass and small reduction can be used, but for a...

AI Technical Summary

Problems solved by technology

[0005] Due to the high reduction efficiency, the current gradual curvature convex roll reduction process can only improve shrinkage defects at the end of solidification, but cannot improve segregation defects at the two-phase region.

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