Abstract
A new internal finishing process is investigated of a non-ferromagnetic tubing applying a rotating magnetic field generated by electromagnetic coils. To finish the inner surfaces of long or vent clean tubings, a new type finishing equipment is made for practical use. This equipment has conically shaped magnetic coils and magnetic cores consisted of laminated thin electric pure iron plates, so that this equipment is able to be applied to the tubings with the wide range outer diameter from 25 to 150 mm and the temperature rise generated by iron loss of the cores were prevented in lower level. Using this equipment, the finishing experiments were carried out to examine the influences of various factors, especially, finishing tool size, tool weight, tool contact curvature and magnetic field strength, on the maximum adulating revolution of the finishing tool. As the result, the suitable finishing conditions were made clear. Then, from the experiment applying this new process to the internal finishing of a stainless steel elbow tubing which could not be rotated, it was clarified that the surface roughness of 15 μmRmax before finishing was improved to 0.4μmRmax after finishing.
