METHOD OF MULTIPLE DRAWING OF WIRE WITH ELECTRIC CONTACT HEATING Russian patent published in 1995 - IPC

FIELD: metal pressure forming. SUBSTANCE: method comprises steps of drawing a wide blank through drawing dies, arranged successively in the same manufacturing flow, and simultaneous passing of an electric current through the blank; providing two zones of electric heating of the blank; first zone is placed between the first and the second drawing dies and the second heating zone is placed between the second and the third drawing dies; passing through the wire in the first heating zone an electric current with density (38-45) A/square mm; selecting a length of the first heating zone, taking into account a time period of wire motion along it, being (0.75-1) s; at the second heating zone passing through the wire the electric current with density (13-22)A/square mm and selecting a length of the second heating zone, taking into account a time period of moving of the wire along it, being (1.2-1.6)s. EFFECT: enhanced quality of products at drawing hard-to-deform materials. 1 cl, 1 dwg, 2 tbl