HRB600E V-Ti microalloyed high-strength anti-seismic hot-rolled steel bar

Abstract

The application discloses an HRB600E V-Ti microalloyed high-strength anti-seismic hot-rolled steel bar. The HRB600E V-Ti microalloyed high-strength anti-seismic hot-rolled steel bar is characterized in that the HRB600E V-Ti microalloyed high-strength anti-seismic hot-rolled steel bar is prepared from the chemical compositions in percentage by mass: 0.22-0.28% of C, 1.50-3.00% of Si+Mn, 0.10-0.25%of V+Ti, less than or equal to 0.12% of V, less than or equal to 0.035% of P, less than or equal to 0.035% of S, 0.02-0.04% of N and the balance of Fe and inevitable impurities; Mn=(1-4)*Si, V=(1-3)*Ti, and the carbon equivalent Ceq=C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15<=0.56. A production method includes the steps of a smelting process, a continuous casting process, a rolling process and a cooling process of a cooling bed. According to the HRB600E V-Ti microalloyed high-strength anti-seismic hot-rolled steel bar, by adding V and Ti microalloy elements, ferro-silicon nitride cored wires are fed in thesmelting process for increasing nitrogen; the process of combination of high temperature heating and low temperature opening rolling is adopted in the rolling process to ensure the solid solution ofthe V and play a fine crystalline role of TiN; and after that, in the cooling process, the dispersed and fine Ti (C/N)+V (C/N) composite particles are formed and precipitated out, and the synergisticeffect of precipitation strengthening and fine crystalline strengthening is achieved. The microstructure of screw-thread steel produced by the compositions and process is ferrite plus bainite, and thelower yield strength is greater than or equal to 620MPa.

Description

technical field [0001] The application relates to the field of iron and steel metallurgy, in particular to a HRB600E vanadium-titanium microalloyed high-strength shock-resistant hot-rolled steel bar. Background technique [0002] With the continuous development of China's economic construction, the requirements for steel bars for construction continue to increase, and high-strength, earthquake-resistant, and economical steel bars will gradually become the mainstream of the market. The new national standard GB / T1499.2-2018 "Steel for Reinforced Concrete Part II: Hot-rolled Ribbed Steel Bars" promulgated in 2018 added 600MPa-grade steel bars and canceled 335MPa-level steel bars. The use of higher-grade building steel bars can save the amount of steel used, reduce the weight of the structure, shorten the construction period, and have remarkable effects in energy saving, emission reduction and environmental protection. The 600MPa-grade high-strength seismic steel bar HRB600E ca...

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Problems solved by technology

Due to the high price of vanadium alloy, adding a large amount will inevitably increase the production cost and affect the profit of the enterprise

However, those who reduce the amount of added vanadium all take the route of finishing rolling and water penetration, such as "a HRB600E high-strength seismic steel bar and its production method" applied by Shaanxi Iron and Steel Co., Ltd. and "Niobium-titanium-boron microalloy HRB600 high-strength seismic steel bar" and its preparation" are all through the process of strong water penetration after finishing rolling. Although the performance meets the requirements, on the one hand, the complex production process requires high water penetration capacity of the equipment, and on the other hand, it is difficult to ensure that the water penetration structure is ferrite+ Pearlite

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