Ultrahigh-hardness high-toughness malleable spray-formed high-speed steel and preparation method thereof

Abstract

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.

Description

Technical field: [0001] The invention belongs to the field of materials and preparation, and specifically relates to a cobalt-free high-hardness and high-toughness spray-formed high-speed steel new material that can be directly forged, and the processes of spray-formation preparation, subsequent thermal processing and heat treatment, etc., invented according to the characteristics of spray-forming Technology and method. Background technique: [0002] Due to the slow cooling rate, the high-speed steel prepared by the traditional method has coarse grains and eutectic ledeburite. Even after subsequent repeated hot forging and hot rolling deformation processes, it is difficult to completely solve the above problems. Usually the grain size is 100-150 μm, the carbide is 10-20 μm, and there is also a skeleton-like morphology. The above-mentioned problems not only restrict the performance improvement of high-speed steel, but it is difficult to break through the hardness of 64-66HRC...

AI Technical Summary

Problems solved by technology

[0005] However, there are currently two major problems in the preparation of the above-mentioned materials by the spray forming process: (1) Design and development of new materials: there is no special design and development of high Performance metal materials, in order to give full play to the comprehensive advantages of materials and processes

There is no report on this new material of spray-formed high-speed steel

(2) In terms of technology: due to the characteristics of spray forming, there have always been problems such as poor consistency in the composition and performance of the deposited billet, and low density, resulting in poor thermoplasticity of the material

[0007] This not only greatly increases the material cost and reduces the finished product rate, but also requires the existing production enterprises to add expensive hot isostatic pressing and hot extrusion equipment, which is difficult Really promote and practical

In addition, it is difficult to make better use of the performance potential of the material

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