Easy-cutting vanadium-feeding high-aluminum nitriding steel and preparation method thereof

The invention discloses easy-cutting vanadium-feeding high-aluminum nitriding steel and a preparation method thereof. The steel comprises, by weight, 0.26%-0.40% of carbon (C), 0.15%-0.50% of silicon (Si), 0.08%-1.50% of manganese (Mn), 0.08%-1.50% of chromium (Cr), 0.05%-0.25% of vanadium (V), 0.10%-0.30% of aluminum (Al), less than 0.020% of phosphorus(P), 0.015%-0.10% of sulphur (S), less than 0.20% of copper (Cu), less than 0.20% of nickel (Ni), less than 0.015% of stannum (Sn), less than 15*10-4% of oxygen (O), the balance ferrum (Fe) and inevitable impurities. The preparation method includes smelting, alloying, continuous casting ingot, and hot rolling process, wherein during an electric-arc furnace smelting process, a control end point [C] is lager than or equal to 0.15%, and a control end point [P] is less than or equal to 0.010%, preliminary dexidation is alloyed in a steel ladle, and 50%-60% of aluminum (Al) is added into tapped steel. Argon is blown during the whole journey of LF refining, and time of keeping white slag is between 15 minutes and 20 minutes. VD vacuum is treated in a degassing mode. Whole journey protection continuous casting ingots are adopted and the steel is manufactured in a hot rolling mode. The high-aluminum nitriding steel is suitable for nitriding hot treatment, nitriding layer is deep after nitriding, high in surface rigidity, and cutting performance of the steel is good.