Vanadium and titanium compound microalloyed steel bar and production method thereof

Abstract

The invention discloses a vanadium and titanium compound microalloyed steel bar and a production method thereof. The steel in the steel bar comprises the following chemical components in percentage by weight: 0.16 to 0.25 percent of C, 0.20 to 0.80 percent of Si, 1.20 to 1.50 percent of Mn, 0.001 to 0.12 percent of Ti, 0.001 to 0.10 percent of V, less than or equal to 0.01 percent of N, less than or equal to 0.045 percent of S, less than or equal to 0.045 percent of P, and the balance of Fe and inevitable impurities. The production method for the steel bar comprises the following steps of: a, smelting crude molten steel, tapping, deoxidizing and alloying; b, refining, trimming the components to make the components meet the component requirement of the steel bar, and casting; and c, performing hot rolling, wherein alloying vanadium and titanium after deoxidizing in the process of tapping, or in the process of refining. According to the vanadium and titanium compound microalloyed steel bar, the yield strength and the tensile strength of the steel are improved under the condition of not changing the ductility of the steel, and the performance requirements of the steel bars in 400 MPa or 500 MPa of grades are met.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy microalloying, and in particular relates to a hot-rolled vanadium-titanium composite microalloyed steel bar for reinforced concrete and a production method thereof. Background technique [0002] At present, my country is in a period of rapid industrialization and urbanization, and the construction industry is developing rapidly to large-scale. The construction industry is developing toward large scale. In order to improve the safety of large buildings, the construction industry at home and abroad generally uses high-strength, high-weldability hot-rolled ribbed steel bars instead of ordinary steel bars. In addition, with the introduction of policies to promote the use of high-strength steel bars in my country, low-strength steel bars below 335 MPa such as HRB335 will be gradually eliminated, and hot-rolled ribbed steel bars of HRB400 and above levels will be vigorously developed. ...

AI Technical Summary

Problems solved by technology

Microalloying carbonitride precipitation strengthening of steel bars with vanadium has been widely used, and the use of micro-titanium treatment to refine the austenite grains of steel bars has also been applied, but at the same time, the use of vanadium-titanium composite microalloying (that is, replacing part of V with Ti) ), it has not been reported that the reinforced steel bar containing the second phase of V is replaced by the second phase of Ti

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