Vanadium-nitrogen additive for smelting microalloyed steel and method for preparing same

Abstract

The invention discloses a vanadium-nitrogen additive for smelting microalloyed steel and a method for preparing same. The vanadium-nitrogen additive and the method are characterized in that the vanadium-nitrogen additive is uniformly mixed by vanadium-contained alloy powder, nitrogen increasing agent powder, and adhesive, wherein the mass ratio of the adhesive is 5-12%, the total mass ratio of the vanadium-contained alloy powder and the nitrogen increasing agent powder is 88-95%, and the ratio of V / N is controlled within 0.1-4. The method for preparing the vanadium-nitrogen additive used for smelting microalloyed steel comprises the following steps: mixing the vanadium-contained alloy powder and the nitrogen increasing agent powder by the weight percentage, mechanically and uniformly blending the mixed powders, subsequently adding 5-12% of the adhesive and uniformly mixing the powders again, finally mechanically forming blocks of spherule shapes or other shapes, and preparing the vanadium-nitrogen additive by drying the blocks. The ratio of V / N of molten steel can be controlled within 3.0-5.0 by the vanadium-nitrogen additive, the enhancement effect of the vanadium can be sufficiently played by utilizing the cheap nitrogen element, and the amount of the vanadium is reduced obviously.

Description

technical field [0001] The invention belongs to the field of metallurgical auxiliary materials, and in particular relates to a preparation method of a vanadium nitrogen additive for smelting microalloyed steel. Background technique [0002] As a microalloying element in steel, vanadium can produce precipitation strengthening and grain refinement by forming carbon and nitride. The addition of vanadium and nitrogen to the steel has a better strengthening effect than adding vanadium alone for microalloying. This is because vanadium nitrides have higher stability than vanadium carbides, and the precipitates are finer and dispersed. Significantly improved. Nitrogen is a very effective alloying element in vanadium microalloyed steel. By making full use of cheap nitrogen, the strengthening effect of vanadium microalloyed steel can be significantly improved, and the purpose of saving alloy consumption and reducing costs can be achieved. [0003] When the steel is microalloyed with...

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Problems solved by technology

However, even VN16 vanadium-nitrogen alloy with higher nitrogen content has a V / N ratio greater than 5, which is much higher than the ideal V / N ratio of 3.64. Since the recovery rate of vanadium during smelting is significantly higher than that of nitrogen, the When adding VN16 vanadium-nitrogen alloy, every 0.01% of vanadium can only bring about 13ppm of nitrogen into the steel, and the V / N ratio actually added to the steel is greater than 7.69, which makes part of the strengthening effect of vanadium element fail to play out

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