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The technology of pulse plasma modification of the working surface of the stamp of 4Kh5MF1S tool steel (analogues: in the EU - X40CrMoV5-1; in China - 4Cr5MoSiV1) is considered. The mentioned tool is used for stamping billets of titanium VT6 alloy (wt.%: Al – 3.0…6.8; V – 3.5...5.0; Ti – base), which is performed at temperatures up to 700 °С. The surface of the stamp is heated, which leads to its oxidation and diffusion redistribution of alloying elements. Pulse-plasma stamping leads to the formation of elastic-plastic deformations of the surface layer in tool steel, which in combination with pulsed thermal and electromagnetic effects provides refinement of the alloy structure and intensifies the diffusion mechanisms of alloying elements. Studies showed that the modified layer (over 80 μm thickness) in 4Kh5MF1S steel, formed in the process of pulse-plasma treatment, contains up to 2.5% carbon, up to 12% oxygen and up to 3% tungsten. In the mentioned layer the presence of nanocrystalline structures with a size of less than 100 nm was revealed. The hardness of the modified layer is more than 700 HV 0.025. The surface roughness after pulse-plasma treatment did not change. Experience of industrial use of this technology showed that modification of a surface of a stamp from 4Kh5MF1S steel provided its high efficiency at deep drawing of products from the heated (to 700 °C) sheet of VT-6 titanium of 3 mm thickness. 11 Ref., 1 Tabl., 6 Fig. [ABSTRACT FROM AUTHOR]

The technology of pulse-plasma modification of the working surface of the die of 4Kh5MF1S tool steel (analogues are X40CrMoV5-1 in the EU and 4Cr5MoSiV1 in China) was considered. The mentioned tool is used for stamping billets of titanium VT6 alloy (wt.%: Al -- 3.0--6.8; V -- 3.5--5.0; Ti -- base), which is performed at temperatures of up to 700 °C. The die surface is heated, which leads to its oxidation and diffusion redistribution of alloying elements. Pulse-plasma stamping leads to the formation of elastic-plastic deformations of the surface layer in a tool steel, which in combination with pulsed thermal and electromagnetic effects provides a refinement of the alloy structure and intensifies the diffusion mechanisms of alloying elements. The studies showed that the modified layer (over 80 µm thickness) in 4Kh5MF1S steel, formed in the process of pulse-plasma treatment, contains up to 2.5 % carbon, up to 12 % oxygen and up to 3 % tungsten. In the mentioned layer the presence of nanocrystalline structures with a size of less than 100 nm was revealed. The hardness of the modified layer is more than 700 HV0.025. The surface roughness after pulse-plasma treatment did not change. Experience of industrial use of this technology showed that modification of a surface of the die from 4Kh5MF1S steel provided its high serviceability at a deep drawing of products from the heated (to 700 °C) sheet of VT-6 titanium of 3 mm thickness. [ABSTRACT FROM AUTHOR]