The invention provides ultrahigh-
hardness high-
toughness malleable spray-formed high-speed steel and a preparation method of the steel, belonging to the field of material and preparation. The steel comprises the following chemical compositions: 1.3-1.8% of C, 6-8% of W, 5-7% of Mo, 4-6% of Cr, 3-5% of V and 1-3% of Nb, wherein Si is less than or equal to 0.4, Mn is less than or equal to 0.4, S is less than or equal to 0.03, P is less than or equal to 0.03, and the balance of Fe. Technologically, the method comprises the following steps of: obtaining a columnar deposition billet with the tissue size being 15-30mum and the
carbide size being 3-8mum on a base plate by adjusting the angle of an atomizing
nozzle, controlling the speed of a pull base plate, heating a deposition plate, slowing down the temperature reduction of deposited steel liquid, and atomizing the solution into
solution drops; annealing under the temperature of 1100-1180 DEG C before the deposition billet is forged, and gradually
forging according to the technology when the deposition billet is forged, wherein the
forging ratio of each fire is not more than 35%, the
forging heating temperature is 1130-1180 DEG C, and the final forging temperature is not less than 900 DEG C; and further refining the sizes of the forged crystalline grain and the
carbide into 10-15mum and 2-5mun. The ultrahigh-
hardness high-
toughness malleable spray-formed high-speed steel and the preparation method of the steel have the advantages of low cost, and short technological process, the cost of the spray-formed high-speed steel is only 1 / 5-1 / 10 of that of the power high-speed steel, and the technological process is reduced by 2 / 3; and the spray-formed high-speed steel has the high
hardness and the red hardness, which are close to those of the similar
powder high-speed steel, and the
toughness of the spray-formed high-speed steel is higher than that of the
powder high-speed steel.