Production method of high-strength cord steel billet

Abstract

The embodiment of the invention discloses a production method of a high-strength tire cord steel square billet. The method comprises the steps of molten iron desulfurization, converter smelting, refining, continuous casting, square billet heating, hot continuous rolling, cooling and collecting and winding; when the continuous casting process is conducted, the water quantity of a mold is controlledto be 3000-4000 L / min, the vibration frequency is 120-125 Hz, the electromagnetic stirring current of the mold is 750 + / - 5 A, the frequency is 1.5 + / - 0.2 Hz, and meanwhile, the secondary cooling section adopts water mist cooling, the water quantity is 16-78 L / min, and the water pressure is 1.0-3.0 bar; in the continuous casting process, when the solid fraction (fs) is 0.5-0.9, 6-section soft reduction is adopted; when square billet heating is conducted, according to the process control requirement, the temperature of a soaking section of a heating furnace is controlled to be 1190-1230 DEG C, the air-fuel ratio is smaller than 0.65, and the heating time is 240-300 min; when hot continuous rolling is conducted, the starting rolling temperature is controlled to be 1050-1080 DEG C, the rolling pass elongation coefficient is 1.1-1.3, and the cross-sectional dimension reduction rate is 14%-23%. According to the method, for the large square billet continuous casting and break-down process,the mold, the secondary cooling section, the dynamic soft reduction, the heating system and the rolling system are designed to improve the purity of molten steel, reduce the segregation of a castingblank and reduce the porosity and the shrinkage.

Description

technical field [0001] The application relates to the technical field of cord steel, and is especially suitable for the production method of high-strength cord steel billets. Background technique [0002] In the prior art, steel cords, commonly known as steel cords, are ideal skeleton materials for rubber products, especially car radial tires. Cord steel is an important raw material for manufacturing steel cords. It is a boutique of high-quality hard wire steel. It is a representative product of ultra-clean steel and a symbol of the production level of wire rods in steel companies. It is also one of the steels with the highest strength in commercial steel. [0003] In the production of cord steel, there are special requirements for every link such as smelting, rolling, and processing. It is precisely because of the high content of production technology that it is also known as "the best in wire rods" and "the pearl in wire rods". Usually, the steel cord needs to be drawn th...

AI Technical Summary

Problems solved by technology

"One fire material" is limited in segregation control due to the limitation of process and compression ratio

There are more and more domestic high-strength cords using the "secondary material" of blooms, but there are still many problems in the quality and surface quality of continuous casting billets, and the product quality is unstable

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