Core-spun thread for increasing N and V in molten steel and use method thereof

The invention relates to a core-spun thread for increasing N and V in molten steel and a use method thereof. The technical scheme is as follows: a preparation method comprises the following steps of: mixing 10-25 percent by weight of V2O5 powder, 20-30 percent by weight of silicon nitride iron powder, 10-25 percent by weight of reducing agents and 35-50 percent by weight of additives; uniformly stirring; and wrapping by using a cladding steel strip to obtain the core-spun thread for increasing N and V in the molten steel. The use method of the core-spun thread for increasing N and V in the molten steel comprises the step of adding the core-spun thread for increasing N and V in the molten steel to the molten steel by using a thread feeder at the terminal stage of a smelting reduction period when a medium-low carbon vanadium-containing alloy is smelted, wherein the addition amount of the core-spun thread is 3-22 kg in per ton of steel. The core-spun thread for increasing N and V in the molten steel, which is prepared by the method disclosed by the invention, has the advantages of easiness and convenience for operation, easiness for implementation, controllability and environmental friendliness, can be used for increasing the V2O5 reduction speed, achieving high and stable vanadium yield and fast obtaining the medium-low carbon vanadium-containing alloy steel with high comprehensive mechanical property and mechanical property through a single step for one time and has an outstanding economic benefit.