Super-thick steel plate for low yield ratio buildings with 460 MPa grade yield strength and manufacturing method

Abstract

The invention relates to a super-thick steel plate for low yield ratio buildings with 460 MPa grade yield strength and a manufacturing method, which belongs to the technical field of high strength low alloy construction steel. The steel pipe comprises the following components by weight percent: 0.14 to 0.18 percent of C, 0.35 to 0.45 percent of Si, 1.40 to 1.50 percent of Mn, 0.025 to 0.035 percent of Nb, 0.040 to 0.050 percent of V, 0.010 to 0.020 percent of Ti, smaller than 0.020 percent of P, and the balance Fe. The rolling technology is as follows: the heating temperature is 1220 to 1250 DEG C, the tapping temperature is 1200 to 1230 DEG C, and two stages (ausrenitic recrystallization region and ausrenitic non-recrystailization region) are used for controlling rolling. The heat treatment technology is as follows: steel plates, the thickness of which is larger than or equal to 80 mm, are obtained after controlled rolling and cooling are carried out on continuously cast bloom, a two-phase region is heated up to 800 to 850 DEG C and insulated for 10 to 20 minutes, and then water quenching is adopted and the final cooling temperature is controlled to be less than or equal to 100 DEG C; 450 to 600 DEG C tempering treatment is carried out on the quenched steel plates, and finally the high strength low alloy construction steel plates are obtained. The steel plate not only has excellent comprehensive mechanical properties, but also lowers the cost and reduces the waste of resources.

Description

technical field [0001] The invention belongs to the technical field of low-alloy high-strength steel for construction, and in particular relates to an extra-thick steel plate for construction with a yield strength of 460 MPa and a low yield strength ratio and a manufacturing method. Tempering heat treatment to realize the production of ultra-thick steel plate Q460GJ with low yield ratio and high strength for construction with a thickness specification ≥ 80mm. Background technique [0002] With the rapid development of my country's national economy, the market demand for thick steel plates for construction is increasing, and the requirements for steel plate thickness specifications are constantly increasing, and performance requirements are constantly improving. The Q345MPa grade steel plate commonly used in the past can no longer meet the development needs of steel structure buildings. Some components of the newly completed CCTV main building, the National Swimming Center, a...

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Problems solved by technology

The Q345MPa grade steel plate commonly used in the past can no longer meet the development needs of steel structure buildings. Some components of the newly completed CCTV main building, the National Swimming Center, and th

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