Investigations have been carried out into the effect of various methods of plastic deformation in the superplasticity temperature range of the high-speed steel on the structure and properties of the welded joint between steel 45 and steel R6M5, and the possibility of transferring the welded joint to the working part of the large bimetallic cutting tool. In the conditions of longitudinal-helical rolling and free wedge forging, the structure of the welded joint is almost unchanged, with simultaneous partial opening of the joint. When using the method of plastic deformation of the Bridgman chamber type (pressure + shearing, hydro-dynamic pressing in closed dies) the ferrite interlayer is disrupted, mixed with the high-speed steel with simultaneous grain refining, and the resultant structure of the welded joint corresponds to the structure of laminated composite and dispersion-hardened materials supporting a smooth transition from the ferritic-pearlitic structure of steel 45 to the martensitic-carbidic structure of R6M5 steel in completed components. This also increases the strength and toughness of the welded joint.
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