600 MPa-grade vanadium-niobium-titanium-nitrogen composite reinforced steel bar and smelting method thereof

Abstract

The invention provides a 600 MPa-grade vanadium-niobium-titanium-nitrogen composite reinforced steel bar and a smelting method thereof. A smelting process is adopted for smelting, in the converter smelting tapping process, according to the amount of 1.80-1.93 kg / t steel, a vanadium-nitrogen alloy FeV77N16 with the N content of 16%, the V content of 77% and the balance Fe and inevitable impurities is added, according to the amount of 0.21-0.37 kg / t steel, ferroniobium with the Nb content of 63.0-65 wt% is added, a titanium wire with the Ti content of 67 wt% is added, and the Ti / N ratio of molten steel is controlled at 3-3.57. According to the method, a titanium-iron alloy is used for replacing part of vanadium-nitrogen alloy for microalloying, so that residual nitrogen in the steel is fully utilized, the Ti precipitation and precipitation strengthening effects are exerted, and the purpose of reducing the consumption of the vanadium-nitrogen alloy is achieved.

Description

technical field [0001] The invention relates to the technical field of steel bar manufacturing technology, in particular to a 600MPa grade vanadium-niobium-titanium-nitrogen composite reinforced steel bar and a smelting method thereof. Background technique [0002] Since 2018, domestic and global vanadium prices have skyrocketed, which has brought severe challenges to enterprises that use vanadium alloying to produce hot-rolled steel bars. The application of vanadium reduction is very necessary. At present, vanadium used in the production of 600MPa high-strength steel bars at home and abroad Nitrogen alloy (FeV 77 N 16 ) consumption is high, the cost is high, and the utilization rate of V is not high. [0003] At present, the production of HTRB600 (E) steel bars uses "vanadium nitrogen + ferroniobium" composite microalloying, the V content in the steel is 0.140%-0.150%, the nitrogen content is 100-200ppm, the nitrogen content is low, and the precipitation strengthening eff...

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Problems solved by technology

[0002] Since 2018, domestic and global vanadium prices have skyrocketed, which has brought severe challenges to enterprises that use vanadium alloying to produce hot-rolled steel bars. The application of vanadium reduction is very necessary. At present, vanadium used in the production of 600MPa high-strength steel bars at home and abroad Nitrogen alloy (FeV 77 N 16 ) is high in consumption and cost, and the utilization rate of V is not high

[0003] At present, the production of HTRB600 (E) steel bars uses "vanadium nitrogen + ferroniobium" composite microalloying, the V content in the steel is 0.140%-0.150%, the nitrogen content is 100-200ppm, the nitrogen content is low, and the precipitation strengthening effect of V (N, C) is not Fully utilized, resulting in high consumption and high cost of vanadium nitrogen alloy

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