Steel for 650MPa-level high-strength explosion-proof fireproof steel bars and heat engine rolling technology of steel

Abstract

The invention relates to the technical field of hot-rolled ribbed steel bars for concrete, and discloses steel for 650MPa-level high-strength explosion-proof fireproof steel bars and a heat engine rolling technology of the steel. The steel comprises the following raw materials in percentage by weight of 0.20-0.30% of C, 0.40-0.80% of Si, 1.20-1.60% of Mn, 0.02-0.05% of Nb, 0.05-0.15% of V, 0.15-0.75% of Cr, 0.20-0.60% of Mo, 0.04-0.06% of Ti, lower than or equal to 0.030% of P, lower than or equal to 0.030% of S and 0.02-0.04% of Fe. According to the steel for 650MPa-level high-strength explosion-proof fireproof steel bars and the heat engine rolling technology of the steel disclosed by the invention, tissue can be refined, low-temperature toughness can be improved, favorable mechanical property can be obtained, and fatigue strength can be improved; the steel has better surface quality; and the comprehensive strengthening means of steel and iron materials including solid solution, deposition and fine-grain strengthening of microalloy elements and fine-grain strengthening of TMCP and the like are comprehensively utilized, so that under the premise that the plasticity of the materialis maintained, the 650MPa-level steel bars which are excellent in comprehensive property are produced, the yield strength is greater than or equal to 650MPa, the tensile strength is greater than or equal to 800MPa, the extensibility after breaking is greater than or equal to 14%, and the total elongation percentage under maximum force is greater than or equal to 7.5%.

Description

technical field [0001] The invention relates to the technical field of hot-rolled ribbed steel bars for concrete, in particular to a steel for 650MPa-level high-strength explosion-proof fire-resistant steel bars and a thermomechanical rolling process thereof. Background technique [0002] Explosions are often accompanied by phenomena such as shock waves, high pressure, high temperature, and the impact of explosion fragments, which have a great destructive effect and bring losses to the lives and property of the people. First, the shock waves generated at the moment of explosion will radiate from the release point and Supersonic diffusion will produce huge lethality and destructiveness when it acts on people or objects. The greater the overpressure value, the greater the lethality and destructiveness, but as the intensity decreases, the propagation speed also gradually decreases; 1. The explosion will generate high temperature, which will ignite combustibles and increase the ...

AI Technical Summary

Problems solved by technology

[0002] Explosions are often accompanied by phenomena such as shock waves, high pressure, high temperature, and the impact of explosion fragments, which have a great destructive effect and bring losses to the lives and property of the people. First, the shock waves generated at the moment of explosion will radiate from the release point and Supersonic diffusion will produce huge lethality and destructiveness when it acts on people or objects. The greater the overpressure value, the greater the lethality and destructiveness, but as the intensity decreases, the propagation speed also gradually decreases; 1. The explosion will generate high temperature, which will ignite combustibles and increase the destructive effect of the explosion; 3. The impact of the explosion fragments will cause harm in a considerable range. The thinner the fragments, the faster the flying speed, and the greater the harm; 4. The explosion will also cause the whole structure of the building or most of the structure to collapse continuously, which will bring difficulties to the reconstruction after the disaster.

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