MIRROR FINISHING FOR LONG SIZE METAL WORKPIECE OUTER CIRCUMFERENTIAL FACE

PROBLEM TO BE SOLVED: To highly precisely and highly efficiently perform mirror finishing of a long side metal workpiece by combined effects of an abrasion action by a grinding wheel and a concentrated elution action by electrolyte. SOLUTION: At first, a rough polishing grinding wheel 5 is pushed against a long metal pipe P fed in an electrolytic combined polishing device 1 by an appropriate prescribed pressure by a cylinder 6 in a rough polishing range A, electrolyte is fed from an electrolyte feeding port 10 to the outer circumferential face of the long metal pipe P, and the outer circumferential face of a passivation coat formed around the outer circumferential face of the long metal pipe P is roughly polished by integrally combining an abrasion action by the rough polishing grinding wheel 5 and a concentrated elution action by electrolyte. Secondly, with forwarding movement of the long metal pipe P, an intermediate polishing in an intermediate polishing region B and a finish polishing in a finish polishing region C are performed in order, that is to say, three-stage polishing of the rough, intermediate, and finishing are performed in order. After polishing, the long metal pipe P is taken out from the electrolytic combined polishing device 1 so as to move a second moving means with holding mechanism.