2400-MPa-strength prestressed steel strand and production process thereof
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A technology of prestressed steel strand and production process, which is applied in metal material coating process, manufacturing tools, temperature control, etc., can solve problems such as difficult production, and achieve the effect of improving tissue uniformity and uniformity
Inactive Publication Date: 2020-06-23
CHINA ACADEMY OF RAILWAY SCI CORP LTD +5
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[0005] The present invention is to solve the problem that the large-scale high-carbon steel wire rod in the prior art needs to ensure the good plasticity and structure of the wire rod while greatly improving the strength, and the production difficulty is extremely high. It provides a 2400MPa-grade The prestressed steel strand and its production process solve the above problems
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Embodiment 1
[0046] A prestressed steel strand with a strength of 2400MPa, its chemical composition includes C0.92%, Si1.20%, Mn0.80%, Cr0.010%, P0.003%, S0.33%, Al0. 0.011%, V0.032%, and the rest are Fe and unavoidable impurities. The diameter of the steel strand is 13 or 14mm.
[0047] The preferred raw material for steel strand production is air-cooled and hot-rolled wire rod with a diameter of Φ14mm and a strength of not less than 1400MPa; the preferred grade of wire rod used is QS92Si-HT, and the C content is 0.9% to 0.95%.
[0048] Such as figure 1 As shown, the production process of 2400MPa grade prestressed steel strand includes the following steps:
[0049] S1. Converter steelmaking: The raw materials are smelted into molten iron by blast furnace, and the molten iron is desulfurized and then smelted in the top-bottom combined blowing converter.
[0050] The raw materials are smelted through blast furnace molten iron→KR or granular magnesium desulfurization→top-bottom combined bl...
Embodiment 2
[0085] A prestressed steel strand with a strength of 2400MPa, its chemical composition includes C0.97%, Si0.80%, Mn0.70%, Cr0.011%, P0.003%, S0.26%, Al0. 0.040%, V0.053%, and the rest are Fe and unavoidable impurities. The diameter of the steel strand is 13 or 14mm.
[0086] The preferred raw material for the production of steel strands is salt bath heat-treated wire rod with a diameter of Φ14mm and a strength of not less than 1500MPa; the preferred grade of wire rod used is PQS92Si-HT and QS92Si after lead bath treatment, and the C content is 0.9%-0.95 %.
[0087] Such as figure 1 As shown, the production process of 2400MPa grade prestressed steel strand includes the following steps:
[0088] S1. Converter steelmaking: The raw materials are smelted into molten iron by blast furnace, and the molten iron is desulfurized and then smelted in the top-bottom combined blowing converter.
[0089]The raw materials are smelted through blast furnace molten iron→KR or granular magnesi...
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Abstract
The invention provides a 2400-MPa-strength prestressed steel strand and a production process thereof. The 2400-MPa-strength prestressed steel strand comprises the following chemical components in percentage by mass: 0.88-1.02% of C, 0.10-1.30% of Si, 0.30-0.90% of Mn, 0.10-0.50% of Cr, less than or equal to 0.015% of P, less than or equal to 0.010% of S, 0.01-0.08% of Al, 0.01-0.10% of V, and thebalance Fe and inevitable impurities. Through processes such as slat bath, the problems that a bad structure and large difference in property of a whole wire rod due to the fact that the cooling rateof the air-blown wire rod is low and uneven are solved, rapid cooling and isothermal phase change of the wire rod are achieved, and the strength and uniformity of the structure property are greatly improved; segregation is at a low level, the structure property is more uniform, no quenching structures influencing use, such as a network carbide and a martensite, exists, and good plasticity is stillmaintained while high strength is ensured; and after the wire rods is subjected to drawing, pulling, stranding, and stabilizing treatment, the strength of the strand reaches 2300 MPa or above and 2400 MPa or above, and can be used for producing the superstrength prestressed steel strands of 2300 MPa and 2400 MPa.
Description
technical field [0001] The invention relates to the technical field of smelting, in particular to a prestressed steel strand. Background technique [0002] At present, the national mainstream prestressed steel strand is 1860MPa grade. It has been used continuously since the 1990s and has not been upgraded. Moreover, the market capacity of prestressed steel strand is huge, and the development prospect is broad. [0003] In 2020, the railway system will complete the revision of the industry standard for high-strength prestressed steel strands, and greatly increase the strength level of prestressed steel strands. It is estimated that the design level of steel strands can be increased to 2300MPa-2400MPa. The main significance of improving the strength of the steel strand is to reduce the amount of steel used in the track beam and the use of cement and other related materials, so as to save energy and reduce consumption, greatly reduce the weight of the track beam, and develop to...
Claims
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Application Information
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