Production method for low-alloy medium-thickness steel plate

Abstract

The invention discloses a production method for a low-alloy medium-thickness steel plate. The low-alloy medium-thickness steel plate comprises, by weight, 0.10%-0.18% of C, 0.15%-0.55% of Si, 1.20%-0.88% of Mn, 0.01%-0.02% of P, 0-0.020% of S, 0.015%-0.050% of Al, 0.28%-0.41% of Ni, 0.04%-0.12% of V and the balance Fe and impurity elements. According to the production method for the low-alloy medium-thickness steel plate, the requirements for the manufacturing industry are met, and the ideas of energy saving, consumption reducing and environment-friendly steel are achieved. The low-alloy medium-thickness steel plate has the characteristics that the alloy content is decreased, center segregation is reduced, and the performance uniformity is improved; the carbon equivalent is decreased, and the welding performance is improved; compared with the performance of a steel plate produced through a traditional method, the performance of the steel plate is greatly improved; some of processes are avoided, the alloy content is decreased, direct hot charging is conducted after continuous casting, and the production cost is reduced; the cost is low, the performance is high, and the welding performance is good.

Description

technical field [0001] The invention relates to the technical field of steel alloys, in particular to a method for producing low-alloy medium-thick steel plates. Background technique [0002] The Q345E steel plate with a thickness specification below 16mm can basically be mass-produced with a modern hot rolling mill and the economy is good; but the medium-thick plate with a thickness specification of 16-60mm has poor production economy. After the promulgation of the national standard GB / T1591-2008, the lower limit of the Mn content of the Q345E steel grade in the standard was cancelled, and the steel mills can produce qualified Q345E medium-thick steel plates by proposing suitable components and TMCP processes according to their own process equipment production conditions. [0003] The national standard GB / T1591-2008 has specific requirements for the chemical composition and performance of 16-60mm Q345E medium-thick steel plates produced by TMCP technology; the recommended i...

AI Technical Summary

Problems solved by technology

[0017] In summary, the main defects of the low-alloy medium-heavy plate produced by the TMCP process in the prior art are: the low-alloy medium-heavy plate produced by the TMCP process has a high Mn content, the center segregation of the continuous casting slab is serious, and there are local defects in the rolled steel plate. Delamination, segregation of the center line of the steel plate often forms martensite or bainite structure, resulting in unqualified impact; in order to ensure the quality of continuous casting slabs, molten steel must be refined outside the furnace

After entering the ladle furnace, desulfurization and temperature adjustment are carried out, which increases the production cost; the high Mn content causes the steel plate to have a high carbon equivalent and poor welding performance; each steel mill is equipped with a modern medium and heavy plate rolling mill, and its capacity cannot be fully utilized, wasting production resource