ELECTROMECHANICAL MANDRELLING METHOD Russian patent published in 2020 - IPC B24B39/02 C21D1/04 C21D7/06 

FIELD: technological processes.

SUBSTANCE: invention relates to electromechanical mandrelling. Mandrel is moved along the axis of the hole and formation of hardened annular sections on the hole surface with different hardness by heating of the said annular sections to the quenching temperature by short-term transmission of electric current through the mandrel contact point to the hole surface. Radial ultrasonic vibrations are applied on the mandrel, simultaneously with the beginning of its movement along the hole.

EFFECT: as a result, the wear resistance of the hole of the part is increased, the axial forces on the tool are reduced, and its resistance is increased.

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