METHOD OF ELECTROMECHANICAL MANDRELING Russian patent published in 2016 - IPC B23D43/00 

FIELD: technological processes.

SUBSTANCE: proposed method comprises displacing mandrel with tension along bore axis and heating bore surface by electric current. Preliminary mandrel is pressed to the lower part of the article hole, space above the mandrel is filled with carbon-containing solution and simultaneous carbonisation and hardening by displacing mandrel relative to machined hole from bottom to top is performed.

EFFECT: higher surface hardness of processed hole of the article made from low-carbon steel, improved heat removal from zone of the mandrel contact with machined surface, reduction of mandrel drawing force through the hole.

1 cl, 1 dwg