A kind of 700mpa high-strength hot-rolled H-shaped steel and its preparation method

Abstract

The invention relates to a metallurgical technology, and specifically relates to 700MPa-grade high-strength hot-rolled H-shaped steel and a preparation method thereof. The 700MPa-grade high-strength hot-rolled H-shaped steel comprises the following chemical components in percentage by weight: 0.05-0.10% of C, 0.20-0.50% of Si, 1.30-1.60% of Mn, not greater than 0.020% of P, not greater than 0.008% of S, 0.32-0.50% of Cu, 0.70-0.90% of Cr, 0.32-0.50% of Ni, 0.20-0.30% of Nb, 0.45-0.60% of V and the balance iron and trace impurities. According to the 700MPa-grade high-strength hot-rolled H-shaped steel and the preparation method thereof, heating and rolling are mainly controlled in a combination manner through a component design; and meanwhile, production for the 700MPa-grade high-strength hot-rolled H-shaped steel is realized by virtue of rapid cooling. The product disclosed by the invention is high in mechanical property, and has a yield strength of greater than 700MPa and a tensile strength of greater than 800MPa. Compared with a preparation method for traditional high-strength steel, the preparation method disclosed by the invention has few production procedures and is low in production cost due to no need of online heat treatment and heat treatment after rolling during a production process.

Description

Technical field [0001] The present invention relates to metallurgical technology. Specifically, the present invention relates to a 700MPa high-strength hot-rolled H-shaped steel and a preparation method thereof. Background technique [0002] As the use of hot-rolled H-beam steel for construction continues to increase in size, higher requirements are placed on the steel materials used. At present, the maximum strength of hot-rolled H-beam steel for construction is only 460MPa. In order to meet the heavy load demand, the thickness of hot-rolled H-beam can only be increased to ensure the stability of steel components, which leads to excessive weight of steel components and restricts hot rolling. Application of H-beam. [0003] 700MPa high-strength hot-rolled H-beam steel is mainly used in various components that need to carry higher loads. This steel has higher strength and can carry higher loads, thereby increasing the weight of the steel structure. At the same time, the product i...

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Problems solved by technology

[0004] In recent years, domestic high-strength steel plate production technology has become increasingly mature, and large-scale production has been formed. However, due to the particularity of hot-rolled H-beam production, in the production process of hot-rolled H-beam, continuous casting, rolling, post-rolling cooling and post-rolling Processes such as heat treatment cannot reach the control level of plate production, which limits the production of high-strength hot-rolled H-beams and seriously restricts the development of high-strength H-beams for construction in my country

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