A kind of high-toughness B-containing hot-rolled low-carbon bainite steel plate and its production method

Abstract

The invention provides a high-toughness B-containing hot-rolling low-carbon bainite steel plate. The high-toughness B-containing hot-rolling low-carbon bainite steel plate comprises the following components in percentage by weight: 0.030 to 0.080 percent of C, 1.50 to 1.80 percent of Mn, 0.10 to 0.40 percent of Si, less than or equal to 0.0050 percent of S, less than or equal to 0.015 percent of P, 0.030 to 0.060 percent of Nb, 0.008 to 0.020 percent of Ti, less than or equal to 0.10 percent of V, 0.020 to 0.060 percent of Alt, 0.0010 to 0.0025 percent of B, 0.20 to 0.50 percent of Cr, less than or equal to 0.30 percent of Mo and the balance of Fe and unavoidable impurities. In the production process of the steel plate, the problems that the existing B-containing hot-rolling low-carbon bainite steel plate has great fluctuation of strength and impact toughness are solved by utilizing a laminar flow section cooling process, the B-containing hot-rolling low-carbon bainite steel plate withsmall fluctuation of strength and impact toughness is obtained, and the application of the high-toughness B-containing hot-rolling low-carbon bainite steel plate to the construction machinery industry is facilitated.

Description

technical field [0001] The invention belongs to the technical field of iron and steel material engineering, and relates to a high-toughness B-containing hot-rolled low-carbon bainite steel plate and a production process thereof, in particular to producing a high-toughness B-containing steel plate using a laminar flow segmental cooling process on a steel coil rolling mill production line. Hot rolled low carbon bainite steel plate. Background technique [0002] In recent years, 80Kg level low-carbon bainite steel plates have been more and more widely used in the construction machinery industry, and the composition system and production process are quite different due to different manufacturers. B (boron) alloys are less expensive and are increasingly used in low carbon bainitic steels. However, due to the large fluctuations in strength and impact toughness of B-containing low-carbon bainitic steels, the TMCP+tempering process is generally used to control the fluctuations in i...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a high-toughness B-containing hot-rolled low-carbon bainite steel plate. The steel plate of the present invention has small fluctuations in strength and impact toughness, effectively solving the problem of existing B-containing low-carbon bainite in the background technology. The problem of large fluctuations in strength and impact toughness of steel plates

[0005] Another object of the present invention is to provide a production method of the above-mentioned high-toughness B-containing hot-rolled low-carbon bainite steel plate. The problem of large fluctuations in strength and impact toughness, and the B-containing hot-rolled low-carbon bainite steel plate with small fluctuations in strength and impact toughness are more conducive to application in the construction machinery industry

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