Production method of steel for 82 B steel stranded wires

Abstract

The invention discloses a production method of steel for 82 B steel stranded wires, belonging to the field of metallurgy. In the production method, the steel for the 82 B steel stranded wires is produced by adopting the process flow comprising the following steps of: rotating furnace primary smelting, LF (Low Frequency) refining, RH (Relative Humidity) refining and continuous casting and pouring of a large square billet, wherein the tail end of a solidification end is dynamically and lightly downwards pressed in the procedure of the continuous casting and pouring of the large square billet. According to the production method disclosed by the invention, technologies, i.e. rotating furnace whole-course bottom argon blowing, argon blowing after tapping, RH vacuum degassing, impurity removal,crystallizer electromagnetic stirring, and the like, are adopted in the process flow, and therefore the clean production of the steel for the 82 B steel stranded wires is realized; an antegrade production organization is achieved; obtained components and the quality of casting blanks all meet the requirements for steel grades, and the total oxygen content (T[O]) in the steel is less than 0.0020 percent; and wire breakage does not appear in the wire drawing process of a product, and therefore the wire broken rate of the wire drawing process is reduced.

Description

technical field [0001] The invention relates to a production method of high-carbon hard wire steel, which belongs to the metallurgical industry. Background technique [0002] 82B steel is mainly used to manufacture high-strength and low-relaxation prestressed steel wire and steel strands and other products. In order to ensure continuous or less breakage during the wire drawing process, there are strict requirements on steel segregation and non-metallic inclusions. At present, the 82B steel produced in China has problems such as large segregation and many non-metallic inclusions, which lead to a high rate of wire breakage in the wire drawing process. When producing steel strands with high quality requirements, only a few manufacturers can provide qualified products. Therefore, improving the cleanliness of steel, controlling slab segregation, and solving the problems existing in the production of steel strand steel can effectively reduce the broken wire rate in the wire drawi...

AI Technical Summary

Problems solved by technology

The above-mentioned technological process "Molten Iron Pretreatment-Converter Smelting-Ladle Furnace Refining (LF Refining)-Billet Continuous Casting" has the disadvantage that it is not conducive to the control of N, H and inclusions in the steel, and it is difficult to meet the requirements of high cleanliness steel. The gas content in the product is greatly affected by the raw material conditions, and T[O] in steel is generally above 20ppm

[0004] In order to solve the control problem of N, H and inclusions in steel, "Wuhan Iron and Steel Technology" No. 2, 2009 proposed a process for producing 82B steel: converter smelting-LF refining-VD (vacuum refining (RH))-LF Refining-billet continuous casting, although the process adopts vacuum degassing method, which effectively controls the control of N, H and inclusions in the steel, but it returns to the LF furnace for refining after degassing, and the production process is too complicated. Increased production organization difficulty and production cost

[0005] In addition, it can be seen from the above documents that the current production of 82B steel adopts billet continuous casting. The advantage of adopting billet continuous casting production is that it can save the billet opening process of rolling, and change the second-fired material to the first-fired material. Reduce production costs; however, from the production practice in recent years, its shortcomings are also more prominent. Due to the high casting speed of the billet casting machine, the subcutaneous quality of the produced billet and poor center segregation, porosity, and shrinkage cavity, even if the billet casting machine is used Electromagnetic stirring at the end of solidification is used to improve the internal quality of the slab. However, due to fluctuations in the casting speed of the casting machine, the position of the end point of solidification changes greatly, while the position of electromagnetic stirring at the end of solidification is fixed, resulting in an unstable effect on quality improvement. The broken wire rate in the process is high. With the improvement of quality requirements of users, it is difficult for the products produced by billets to meet the high quality requirements.

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