Q420GJD-Z35 steel plate with thickness of less than or equal to 60 millimeters for high-rise building and production method thereof

Abstract

The invention discloses a Q420GJD-Z35 steel plate with thickness of less than or equal to 60 millimeters for a high-rise building and a production method thereof. The steel plate comprises the following chemical components in percentage by mass: 0.10 to 0.17 percent of C, 0.20 to 0.50 percent of Si, 1.20 to 1.60 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, less than or equal to 0.10 percent of microalloyed elements (Nb+V+Ti), less than or equal to 0.050 percent of Als and the balance of Fe and residual elements. The production method comprises the steps of performing converter smelting, ladle furnace (LF) refining, vacuum refining, continuous casting, heating, rolling, cooling control, slow cooling and heat treatment. Optimized components and a rolling process are controlled strictly, so that the material quality of the product reaches the Q420GJD-Z35 level, the yield strength is controlled to be between 400 and 480 MPa, the tensile strength is controlled to be between 540 and 630 MPa, the yield ratio is less than or equal to 0.80, the elongation ratio is controlled to be between 22 and 27 percent, V-type impact power at -20 DEG C is controlled to be between 153 and 280 J, the Z-direction performance is distributed between 32 and 57, the average value of three Z-direction performance of a single sample is over 40 percent, and the performance index completely meets the Q420GJD-Z35 development requirement.

Description

technical field [0001] The invention relates to steel products, in particular to a Q420GJD-Z35 steel plate for high-rise buildings with a thickness of ≤60 mm and a production method thereof. Background technique [0002] With the rapid development of my country's national economy, the development of steel for high-rise buildings is also developing in the direction of extra thick, extra wide and high performance. The steel used in high-rise buildings puts forward higher requirements on the strength and toughness of the steel plate, the yield strength ratio, and the lamellar tear resistance. Since the steel used in high-rise buildings has requirements on the upper limit of the strength and the yield ratio index, the current grade D and above Steel plates for high-rise buildings are usually alloyed. Unreasonable alloy ratios can easily lead to excessive strength, unreasonable yield ratio, or substandard Z-direction performance. The pass rate of steel plants that can be produced...

AI Technical Summary

Problems solved by technology

The steel used in high-rise buildings puts forward higher requirements on the strength and toughness of the steel plate, the yield strength ratio, and the lamellar tear resistance. Since the steel used in high-rise buildings has requirements on the upper limit of the strength and the yield ratio index, the current grade D and above Steel plates for high-rise buildings are usually alloyed. Unreasonable alloy ratios can easily lead to excessive strength, unreasonable yield ratio, or substandard Z-direction performance. The pass rate of steel plants that can be produced in China is not high.

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