TMCP type bridge steel plate with small same-plate strength difference and production method thereof

Abstract

The invention discloses a TMCP type bridge steel plate with small same-plate strength difference and a production method thereof. According to the production method, a continuous casting billet is sequentially and continuously subjected to a heating procedure, a recrystallization zone rolling procedure, an intermediate billet head and tail shielding and cooling procedure, a non-recrystallization zone rolling procedure and a cooling procedure to be manufactured into the bridge steel plate, in the intermediate billet head and tail shielding and cooling procedure, multi-stage cooling is carried out on a intermediate billet until the intermediate billet is cooled to the final cooling temperature of 860 DEG C + / -15 DEG C and the temperature difference between the head, the middle and the tail of intermediate billet is smaller than or equal to 30 DEG C; and the cooling process of each stage comprises the following steps of determining head and tail low-temperature parts and shielding percentage of the intermediate billet according to a temperature detection result of a whole plate; carrying out non-shielding water cooling on the middle main body of the intermediate billet; and meanwhile,carrying out shielding cooling on the head and tail low-temperature parts according to the determined shielding percentage. The same-plate strength difference of the obtained bridge steel plate is smaller than or equal to 30 MPa, the structure is uniform, the plate shape is good, the head and tail excision amount is reduced, the yield and percent of pass are improved, and the short-length rate ofthe steel plate is reduced.

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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