Spray formed cold work tool steel

Abstract

The invention relates to a spray formed cold work tool steel, which comprises the following chemical components by mass percent: 1.0%-1.5% of C, 0.1%-0.5% of W, less than or equal to 2.0% of Mo, 11.1%-15.2% of Cr, 0.6%-1.5% of V, 0.2%-1.0% of Nb, 0.05%-0.5% of Co, less than or equal to 0.5% of Si, 0.2%-0.6% of Mn, 0.1%-0.8% of N, and the balance iron and impurities. The carbide of the spray formed cold work tool steel is MC carbide and M7C3 carbide, wherein the type of the MC carbide is (V, Nb)(C, N). The prepared spray formed cold work tool steel has uniformly distributed carbide with fine particle size, and has excellent wear resistance and toughness. The invention employs the spray forming process for preparation, the preparation cost is lower than that of powder metallurgy process, thus being beneficial to reduction of the overall cost of alloy.

Description

technical field [0001] The invention relates to a cold work tool steel, in particular to a spray-formed cold work tool steel. Background technique [0002] Cold work tool steel should have excellent performance in four aspects including wear resistance, impact toughness, bending strength and hardness. Under normal use conditions, the wear resistance determines the length of service life. The wear resistance of tool steel depends on the hardness of the matrix and the content, shape and particle size distribution of the hard second phase in the steel. Hard second phases in steel include M 6 C.M 2 C.M 23 C 6 , M 7 C 3 And MC, etc., the microhardness of MC carbide is higher than that of other carbides, which can better protect the matrix during operation, thereby reducing the occurrence of wear and improving the service life of tools and dies. The impact toughness of tool steel is an important indicator to reflect the toughness. The existence of coarse carbides in steel c...

AI Technical Summary

Problems solved by technology

[0003] At present, the tool steel is mainly prepared by the traditional casting and forging process. The tool steel prepared by the casting and forging process is limited by the slow cooling and solidification of the molten steel in the process. The alloy composition is prone to segregation during the solidification process, forming a coarse carbide structure. Subsequent forging and rolling treatment, this bad structure will still have a negative impact on the properties of the alloy, resulting in a low level of cast and forged tool steel performance, including strength, toughness, wear resistance, and grindability, which is difficult to meet high-end processing and manufacturing. Requirements for material performance and life stability

The preparation of tool steel by powder metallurgy solves the problem of segregation of alloy elements, and the prepared alloy structure is fine and uniform. Compared with cast and forged alloys, the performance is greatly improved, but the problem is that the powder metallurgy process is complicated, the process is long, and the cost is high. Improvement, limiting the widespread use of powder metallurgy tool steel

The preparation of tool steel by spray forming process has been reported, but due to the unreasonable ratio of raw material components, the carbide structure of the produced tool steel is not ideal, and its performance is not excellent enough.

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