tmcp type bridge steel plate with small strength difference between the same plates and production method thereof

Abstract

The invention discloses a TMCP type bridge steel plate with small strength difference between the same plates and a production method thereof. In the production method, the continuous casting slab is successively processed into a bridge steel plate through the heating process, the rolling process in the recrystallization zone, the head and tail blocking cooling process of the intermediate billet, the rolling process in the non-recrystallization zone, and the cooling process. In the shading cooling process, the intermediate billet is cooled in multiple stages until the intermediate billet is cooled to a final cooling temperature of 860±15°C and the temperature difference between the head, middle and tail of the intermediate billet is ≤30°C; the cooling process of each stage includes: According to the temperature detection results of the entire plate , determine the head and tail low-temperature parts and the shading percentage of the intermediate billet; perform unshielded water cooling on the middle body of the middle billet, and at the same time perform shading cooling on the head and tail low-temperature parts according to the determined shading percentage. The resulting bridge steel plate has a strength difference of less than or equal to 30 MPa, a uniform structure and a good plate shape, reduces head and tail cuts, improves the finished product rate and pass rate, and reduces the short-length rate of the steel plate.

Description

technical field [0001] The invention belongs to the technical field of material preparation, and relates to a production method of a TMCP bridge steel plate with a small strength difference between the same plates, and a TMCP bridge steel plate with a small strength difference between the same plates prepared by the production method. Background technique [0002] With the rapid development of expressways and high-speed railways in my country, the rapid development of steel bridge manufacturing industry has been promoted. Steel bridges are developing toward multi-functional, multi-lane, heavy-load, long-span and other directions while satisfying functionality. Structural steel for bridges is mainly used in key projects such as the construction of railways, highways, sea-crossing, and river-crossing bridges. Due to the particularity of the use environment, it has strict requirements on comprehensive performance, such as high strength, high toughness, low yield ratio, weldabi...

AI Technical Summary

Problems solved by technology

[0009] In order to solve the problem of large head, middle and tail strength differences of the existing TMCP steel plates, the purpose of the present invention is to provide a production method of TMCP bridge steel plates with small strength difference between the same plates, and a same steel bridge steel plate prepared by the production method. TMCP type bridge steel plate with small plate strength difference, the strength difference between the head, middle and tail of the bridge steel plate is small, the structure is uniform and the plate shape is good, which can effectively reduce the cutting amount of the head and tail of the large plate, improve the yield and qualification rate, and reduce the short length rate of the steel plate

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