Q345q-series super-thick bridge steel plate and production method thereof

Abstract

The invention discloses a Q345q-series super-thick guaranteed performance and flaw detection bridge steel plate comprising the following chemical components in percentage by mass: 0.08-0.16 percent of C, 0.20-0.50 percent of Si, 1.15-1.60 percent of Mn, not more than 0.020 percent of P, not more than 0.010 percent of S, not more than 0.12 percent of microalloyed element (V+Nb+Ti+Ni), 0.010-0.050 percent of AlS and the balance of Fe and residual elements; and carbon equivalent is not more than 0.43. The invention also discloses a production method of the steel plate, comprising the steps of rolling, cooling, straightening, cooling in pile and thermal treatment. In the rolling, the cooling and the straightening, the 130 mm super-thick Q345qD(E) steel plate is successfully developed in the production line of a converter, die casting, mill rolling and normalization thermal treatment through carrying out reasonable composition design, die casting, TMCP (Thermal Mechanical Control Process) rolling and thermal treatment; the secondary flaw detection qualification rate reaches 90 percent, the performance initial test qualification rate reaches 100 percent, and the Z-direction performance of the entity of the steel plate can reach Z15 level. The development of the super-thick steel plate satisfies the higher requirements on bridge industry.

Description

technical field [0001] The invention relates to steel products, in particular to a Q345q series extra-thick bridge steel plate and a production method thereof. Background technique [0002] With the rapid development of my country's national economy, the development of bridge steel is also developing in the direction of extra thick, extra wide and high performance. Steel for bridge structure is widely used in the main body of various long-span bridges, and it is required to be able to avoid large static and dynamic loads and have a long service time. The ability to resist lamellar tearing puts forward higher requirements, and the demand for bridge steel with high strength, excellent low temperature toughness and good welding performance continues to increase. At present, there are not many domestic steel mills that can produce bridge slabs with a thickness of more than 100m, but for the Q345q series (including: Q345qC steel, Q345qD steel and Q345qE steel) with a thickness o...

AI Technical Summary

Problems solved by technology

At present, there are not many domestic steel mills that can produce bridge slabs with a thickness of more than 100m, but for the Q345q series (including: Q345qC steel, Q345qD steel and Q345qE steel) with a thickness of more than 100111m Unable to produce due to special requirements

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