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 displaced along hole axis and formation of hardened annular sections with different hardness on the hole surface by heating of said annular sections to hardening temperature by short-term transmission of electric current through contact point of mandrel with hole surface. From the moment of mandrel movement beginning along the hole, it is simultaneously rotated with translational motion.

EFFECT: higher accuracy of machined bore.

1 cl