Production method for preventing cracks of ingot forming niobium-vanadium double-added low-alloy high-strength steel

Abstract

The invention discloses a production method for preventing cracks of ingot forming niobium-vanadium double-added low-alloy high-strength steel. The production method comprises a smelting procedure, apouring procedure and a solidification and demolding procedure. According to the method, the problem of cracks of the ingot forming niobium-vanadium double-added low-alloy high-strength steel is effectively solved, brand-new combination and proportion are adopted, a high-C low-Mn system is adopted, Nb+V elements are added, a peritectic reaction area is avoided fundamentally, an unbalanced structure is not produced, and a large amount of structure stress is reduced. The pouring process with low pouring superheat degree and long pouring time is adopted in the process, so that the diffusion degree of alloy elements in the high-alloy steel is effectively reduced, and composition segregation and structure segregation are slowed down. After pouring of a die casting, an annealing process in a furnace is added, an isometric crystal area with the characteristic of completely free columnar crystals or isometric crystals is added, and the internal structure is stabilized.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a production method for preventing cracks in ingot-forming niobium-vanadium double-added low-alloy high-strength steel. Background technique [0002] At present, in many large steel plate enterprises producing micro-alloyed steel plates in China, surface quality defects of steel plates have always existed in major steel mills, especially the problem of steel plate cracks, which leads to the deterioration of steel plate mechanics, which not only increases the slab degradation and scrap rate, but also directly Affect the use and processing of steel plates. Steel plate crack defects have long been a major problem for major steel mills. Due to many influencing factors, most of them can only reduce the incidence and cannot be fundamentally solved despite the great efforts of scientific researchers and production practitioners. [0003] For low-alloy high-strength steel...

AI Technical Summary

Problems solved by technology

[0002] At present, many large-scale steel plate enterprises that produce micro-alloy steel plates in China have always had steel plate surface quality defects in major steel plants, especially steel plate cracks, which lead to deterioration of steel plate mechanics, which not only increases the degradation and scrap rate of slabs, but also directly Affect the use and processing of steel plates

However, if the control is not good, a large amount of carbonitrides of AlN and (Nb, V) will precipitate at the grain boundary, which will reduce the plasticity of the steel and produce microcracks

At the same time, production practice shows that the thicker and wider the steel plate, the easier it is to produce cracks and quality defects, and it is more likely to cause abnormal structure at the edge of the steel plate, poor compactness, and reduced impact toughness and strength.