Production method of HRB400E high-strength anti-seismic steel bars containing vanadium element and niobium element and steel

Abstract

The invention discloses a production method of HRB400E high-strength anti-seismic steel bars containing a vanadium element and a niobium element. The production method comprises the following steps that the dosage of each raw material is calculated according to the proportion of the elements of the steel bars to be prepared and the content of each element in the raw materials, and the raw materials are prepared for later use; a converter is shaken to a molten iron mixing position, scrap iron is added into the converter, molten iron is added again, and twice blowing is carried out until the temperature of the molten steel in the converter ranges from 1,670 DEG C to 1,680 DEG C, wherein the content of C element in the molten iron is greater than or equal to 0.06%, the content of P element isless than or equal to 0.035%, and the content of S element is less than or equal to 0.040%; tapping is carried out, and a steel ingot can be obtained by tapping and stabilizing for 5 to 10 minutes; and continuous casting and rolling are carried out in sequence to obtain the niobium-vanadium micro-alloyed HRB400E high-strength anti-seismic steel bars. According to the production method, on the premise of ensuring the strength of the steel bars, the use amount of V element in the high-strength anti-seismic steel bars is reduced, so that the production cost is further reduced.

Description

【Technical field】 [0001] The invention belongs to the technical field of iron and steel smelting and metal material processing and forming, and in particular relates to a production method of HRB400E high-strength anti-seismic steel bars containing niobium vanadium elements and steel products. 【Background technique】 [0002] High-strength anti-seismic steel bars refer to rebars with a strength above 335. At present, HRB400E high-strength anti-seismic steel bars in the iron and steel industry mostly use vanadium nitrogen or ferroniobium for microalloying alone. [0003] For vanadium-nitrogen microalloying, when V element is added, since the solid solution temperature of V element is generally lower than the steel rolling temperature, the grain growth and coarsening will be made after the addition of V element. The strengthening effect is also not obvious. In addition, with the further increase of environmental protection pressure in recent years, the price of vanadium-nitrog...

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Problems solved by technology

In addition, with the further increase of environmental protection pressure in recent years, the price of vanadium-nitrogen alloy as a production raw material has soared, from 130,000 yuan / ton in 2016 to 480,000 yuan / ton in 2018, making V microalloyed HRB400E The cost of steel alloys produced by the process is relatively high, which is not conducive to enterprises to reduce costs and increase efficiency

[0004] For niobium-iron microalloying, the addition of Nb element will reduce the transformation point, increase the nucleation driving force, and make the ferrite and bainite transformation proceed at a lower temperature, thereby forming an ultrafine structure, while The amount of Nb dissolved in austenite is limited, so that the strengthening effect is limited

In addition, in the production process, in order to ensure that the carbonitride of Nb is fully dissolved in the austenite, a higher heating temperature of the billet is required, resulting in higher oxidation and burning loss of the billet, and cracks in the continuous casting billet, and sometimes there is steel bar yielding Phenomena that are not obvious

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