Production method for medium-high carbon high-strength steel homogenized casting blank

Abstract

The invention relates to a production method for a medium-high carbon high-strength steel homogenized casting blank. The invention adopts the technical scheme that the production method comprises the step that a compound filler cored wire is fed into medium-high carbon high-strength molten steel in a continuous casting crystallizer or an ingot mold, wherein the fed compound filler cored wire accounts for 0.3 to 1.2 percent by weight of the medium-high carbon high-strength molten steel, the feeding speed Vband of the compound-filled cored wire is equal to A*Vcasting*(Ttundish -Tliqudus) / Tliqudus, and the vibrating frequency of a band feeding machine is 50-35,000 Hz; the compound filler cored wire is a mixture of passivated iron sand and a high-melting-point carbonitride, the carbonitride accounts for 1-10 percent by weight of the compound filler cored wire, and the high-melting-point carbonitride is a carbonitride formed by Zr and / or Nb. The production method provided by the invention is simple in process, low in cost and convenient to operate; the macrostructure of the produced medium-high carbon high-strength steel homogenized casting blank is obviously improved, and axial / central segregation and internal cracks caused by chemical elements are remarkably reduced or eliminated, so that the plasticity and toughness of a rolled steel plate are improved.

Description

technical field [0001] The invention belongs to the technical field of casting. In particular, it relates to a method for producing a homogeneous cast slab of medium-high carbon and high-strength steel. Background technique [0002] Mold and ingot mold are very critical "heart" parts in casting. The solidification process of molten steel in mold and ingot mold has a decisive impact on the surface quality and internal quality of the billet. Axial / central segregation of cast slabs and blooms has a significant effect on the quality of the finished steel. The ever-increasing demand for high-quality steel makes technicians face the problem of how to reduce the axial / central segregation of continuous casting billets and blooms, and produce high-quality continuous casting billets and blooms that meet high requirements. Continuous casting billets are formed under highly extended liquid phase conditions up to tens of meters, which can seriously affect the development of structural ...

AI Technical Summary

Problems solved by technology

[0004] Compared with the traditional die casting process, the continuous casting process is a major technological advancement, but inherent product defects such as low equiaxed grain rate, center segregation, center looseness and center cracks restrict the quality of continuous casting products

For example, "A Control Method for Light Reduction Position of Slab Continuous Casting" (CN200510028601.4) and "Electromagnetic Stirring Technology for Horizontal Continuous Casting" (CN200510032537.7) can partially Improve slab quality, but these measures require large investment, high requirements for stable operation of steelmaking and continuous casting, complex control models and many influencing factors

At the same time, because the above two technologies are greatly affected by the chemical composition of the steel grade and its mass percentage (wt%) and process parameters (molten steel temperature, casting speed, cooling water and continuous casting machine state, etc.), the uniformity of the billet structure difficult to control