A 600mpa grade green heat-treated high-strength steel bar and its processing method

Abstract

The invention discloses a 600MPa-grade green-heat-treatment high-strength steel bar and a processing method thereof. The high-strength steel bar comprises 0.18-0.3wt% of C, 0.6-1.1wt% of Si, 1.0-1.9wt% of Mn, 0.05-0.2wt% of Cr, 0.01-0.05wt% of Nb, 0.01-0.05wt% of V, and the balance Fe. The high-strength steel bar has the advantages of realization of the yield strength reaching 600MPa, no disappearance of the yield point elongation with the prolongation of time, high tensile strength, high plasticity, less processing making pollution, steel saving and low cost.

Description

technical field [0001] The invention relates to a steel bar and a processing method thereof, in particular to a 600MPa grade green heat-treated high-strength steel bar and a processing method thereof. Background technique [0002] At present, due to the development of real estate business, machinery business, etc., the demand for steel has greatly increased, and people's requirements for steel are getting higher and higher. In the "Twelfth Five-Year Plan" of the national steel industry, it is proposed to "accelerate the elimination of 335 MPa thread Reinforcement bars", "Research on the seismic performance of high-strength steel bars and high-strength concrete structural members, and carry out research and development of 600 MPa and above rebar products". Now many large steel factories are trial-producing HRB600 rebars mainly by adding "V" or " VN" alloy to achieve the purpose of improving the strength, the addition amount reaches about 0.15%, as we all know, the cost of add...

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Problems solved by technology

[0002]At present, due to the development of real estate business and machinery business, the demand for steel has greatly increased, and people's requirements for steel are also getting higher and higher. In the second five-year plan, it was proposed to "accelerate the elimination of 335 MPa grade threaded steel bars", "strengthen the research on the seismic performance of high-strength steel bars and high-strength concrete structural members, and carry out the research and development of 600 MPa class and above threaded steel bars". Now many large steel factories Trial production of HRB600 grade rebar mainly achieves the purpose of increasing strength by adding "V" or "VN" alloy, and the addition amount reaches about 0.15%. As we all know, the cost of adding alloy will increase by 300-400 yuan, and large-scale production of this Due to the limitation of alloy composition change, production speed, smelting and rolling process and other factors in the variety of steel bars, the quality of the produced products is not stable, and the phenomenon of low strength and unqualified strength-to-yield ratio often occurs, especially for specifications below 14mm. more serious products

The steel disclosed in the invention patent (application number: 201110086374.6) is produced through the process of composition ratio, heating, cooling, quenching and tempering. Power consumption cost, but its plasticity is low and the strength ratio is small, and it is prone to instantaneous fracture, resulting in overall fracture and other accidents. In addition, the existing heat-treated high-strength steel processing methods have serious environmental pollution, waste of electric energy and steel resources, and high production costs. High disadvantage