ELECTROLYTIC POLISHING METHOD FOR INSIDE SURFACE OF METALLIC PIPE

摘要

PURPOSE:To obtain high surface roughness with a good polishing rate by inserting an electrode rod which is freely movable in the longitudinal direction of a metallic pipe and is applied with an insulating film except in the energizing part into the metallic pipe, moving said rod, feeding an electrolyte into the pipe and conducting electric current of a square wave of specific conditions between the metallic pipe and the electrode rod. CONSTITUTION:The electrode rod 2 which is freely movable in the longitudinal direction of the metallic pipe 1 and is applied with the insulating film 3 except in the energizing part is inserted into the metallic pipe 1. The electrolyte 7 is fed into the metallic pipe 1 and while the electrode rod 2 is moved in the metallic pipe 1, the electric current of the square wave is conducted between the metallic pipe 1 and the electrode rod 2 to electrolytically polish the inside surface of the metallic pipe 1. The average anodic current density is specified to =60A/dm2 in this stage and the ratio between the current density of the high current and the current density of the low current with respect to the average current density in this stage is kept within a 10-80% range.