A kind of production method of high-carbon high-alloy bearing steel large round billet

Abstract

The invention provides a production method of a high-carbon and high-alloy bearing steel large circular blank. The production method comprises the following steps: an electric furnace is used for slagless tapping; after tapping, a ladle refining furnace refines for quick deoxidation slagging; high-cleanness molten steel with lower contents of inclusions and gas is obtained by vacuum degassing treatment and soft blowing after blasting; the obtained molten steel is cast in a tundish through argon blowing protection; an alkaline low-carbon covering agent is added above the liquid surface of the molten steel in the tundish; the molten steel in the tundish is injected in a crystallizer through an integral leaching water port; electromagnetic stirring of the crystallizer is adopted; crystallizer protection slag is added; a slag line is changed every other 8-10 furnaces to form a continuous-cast blank shell containing the molten steel in the tundish; the secondary cooling strength of the continuous-cast blank shell is controlled; a cooling mode of a secondary cooling area adopts air water atomization cooling; the molten steel in the tundish is cooled to obtain a primary continuous-cast large circular blank; and the primary continuous-cast large circular blank is straightened by adopting a multi-point continuous straightening method to obtain a continuous-cast large circular blank.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a production method of a high-carbon high-alloy bearing steel large round billet. Background technique [0002] Bearing steel is a special steel with high alloy content, good performance and the most widely used. It is often used to manufacture balls, rollers and bearing rings. [0003] At present, there are many patent documents and professional documents on the production of bearing steel continuous casting round billets, disclosing various production processes for producing bearing steel continuous casting round billets. However, for large-section bearing steel continuous casting round billets, often due to factors such as poor purity of molten steel, unreasonable cooling intensity and uniformity, and unsuitable process parameters, it is easy to cause inclusions, high gas content, and uniform composition and structure. It is difficult to meet the performance...

AI Technical Summary

Problems solved by technology

However, for large-section bearing steel continuous casting round billets, often due to factors such as poor purity of molten steel, unreasonable cooling intensity and uniformity, and unsuitable process parameters, it is easy to cause inclusions, high gas content, and uniform composition and structure. Poor performance, intermediate cracks, central cracks, central shrinkage cavities, central segregation and other internal quality defects, it is difficult to meet the performance requirements of the product

[0004] As the diameter of the continuous casting round billet section of this steel type continues to increase, such as figure 2 As shown, the difficulty of production process and quality control has also increased, and the problem of continuous casting slab warping has appeared, and the problem of transverse fracture of the casting slab caused by improper slow cooling of steel

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