Production method of low-alloy grain refinement type HRB400E reinforcing steel bar

Abstract

The invention provides a production method of a low-alloy grain refinement type HRB400E reinforcing steel bar. The production method comprises the following steps of steel billet heating, rough rolling, intermediate rolling, pre-finish rolling on a pre-finish rolling machine, two-time cutting, primary controlled cooling, primary finish rolling, secondary controlled cooling, secondary finish rolling, water cooling, double-length flying shear shearing, cooling on a cooling bed and natural aging. The steel bar comprises the following elements in percentage by mass: 0.20%-0.25% of C, 0.40%-0.70% of Si, 0.90%-1.20% of Mn, less than or equal to 0.045% of P, less than or equal to 0.045% of S and the balance of Fe. The method has the advantages that the temperature control range can be enlarged by rolling the segmented single wires and cooling the segmented single wires by the aid of multi-stage water tanks, uniform cooling and deformation can be guaranteed, ferrite and pearlite structures can be obtained, crystal grains can be refined, the grain size ranges from 9.0 to 10.5, the mechanical properties of the reinforcing steel bars can be guaranteed, and alloy resources can be saved.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a production method of a low-alloy grain-refined HRB400E steel bar. Background technique [0002] The production process of hot-rolled ribbed steel bars has been in the process of development and improvement. There are mainly two representative processes in domestic steel mills: post-rolling water penetration process and high-alloy hot-rolling process. It is produced by the post-rolling water-piercing process with low alloy demand. The yield strength of the steel bar produced by this process can meet the standard, and the manufacturing cost is also saved a lot. However, the steel is easy to rust, and the aging strength is greatly reduced, which is not suitable for strict quality requirements. building concrete. The other uses a high-alloy hot-rolling process to improve the strength of steel bars by adding high manganese, high silicon, and strategic V, Nb and ot...

AI Technical Summary

Problems solved by technology

However, there are few reports on the fine-grain structure in the field of hot-rolled steel bars. Therefore, it is necessary to start from the role of controlled rolling and controlled cooling of rolled steel, and combine the adjustment of silicon, manganese, and vanadium alloy elements to optimize the composition structure and stabilize the steel. Mechanical properties, thereby increasing the added value of steel

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