ELECTROCHEMICALLY POLISHING METHOD AND ITS DEVICE FOR INSIDE METAL PIPE

PURPOSE:To electrochemically polish inside a long scaled metal pipe to predetermined surface roughness, by supporting an electrode to be moved holding a space with an internal wall by supporters in the metal pipe and circulating an electrolyte to flow in the metal pipe. CONSTITUTION:A device, providing blocking members, 2, 3 in both ends of a metal pipe 1 being a work to be polished, inserts an electrode 4 penetrating through the both blocking members 2, 3. Said electrode 4, being supported by supporters 5, 6 in the metal pipe 1, holds a distance between the electrode and a pipe wall. The blocking member 2, providing in its central part a hole 10 for the electrode 4 to pass through, is sealed by providing an O ring 11 in said hole 10. The device, providing a packing 12 in the surface of a recessed part inside the blocking member 2, seals an end surface of the metal pipe 1. An elctrolyte L, being fed from a supply path 14 via a ring groove 13, is supplied in a dispersed condition from a jetting port 15 into the metal pipe 1. The different blocking member 3, being also constituted similarly to the blocking member 2, provides many discharge ports 22.