Cogging method for reducing surface decarburization depth of medium-high carbon steel blank

Abstract

The invention provides a cogging method for reducing the surface decarburization depth of a medium-high carbon steel blank, which comprises the following steps: calculating the number N = T / t of bloom blanks in a heating furnace according to the heating time T required for the bloom blanks to meet the rolling conditions and the time t for rolling each bloom blank; the bloom blank is added into a heating furnace provided with a preheating section, a first heating section, a second heating section and a soaking section to be heated, then high-pressure water with the pressure larger than or equal to 20 MPa is used for descaling the bloom blank, and the bloom blank is rolled after descaling; a small square billet obtained after rolling is subjected to water cooling through a multi-section water cooling device, the surface temperature of the small square billet is reduced to 570-630 DEG C, and finally the small square billet is conveyed to a cooling bed to be subjected to air cooling; the multi-section water cooling device is composed of a plurality of groups of nozzles which are arranged at intervals and can adjust water volume, each group comprises a plurality of nozzles, and the plurality of nozzles in each group are arranged on the periphery of the small square billet. The time of the blank at high temperature is shortened, and the thickness of a decarburized layer is reduced.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy manufacturing, in particular to a blanking method for reducing the surface decarburization depth of a medium-high carbon steel billet. Background technique [0002] Blooms (section size greater than 220mm×220mm) have the advantages of high cleanliness, good uniformity, and good surface quality, and are mainly used to produce high-quality steel such as bearing steel, spring steel, and cord steel. Due to the large section size, it is impossible to directly roll on the high-speed wire, and the bloom needs to be opened. [0003] The bloom has a large section size and high deformation resistance. It is necessary to heat the billet to a higher temperature and hold it for a long time before rolling. After the rolling is completed, the billet is sent to the cooling bed for air cooling. [0004] However, in the existing technology, there is often a serious decarburization problem when th...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a blanking method that reduces the surface decarburization depth of medium and high carbon steel billets, and solves the problem of deep decarburization layer produced during blooming into billets in the prior art, which affects the subsequent The problem that the finished rods and wires are inherited during rolling will affect the performance of the rods and wires. The blanking method provided by the invention can greatly reduce the thickness of the decarburized layer, achieve the effect of reducing the amount of grinding or even avoid grinding, and reduce the production cost. Increased yield

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