METHOD AND DEVICE FOR PRODUCING HIGH STRENGTH RING

摘要

PURPOSE:To increase the strength of a reinforcing ring and to increase the earthquake resistance of a reinforced concrete structure by hardening with rapid cooling the welding zone and by annealing and heating as well after forming the wire rod to which the prescribed strength is given in a ring member and welding with electrifying to the vicinity of both ends. CONSTITUTION:Both end faces of the regular-sized material W to which the prescribed mechanical property is given by heat treatment is made in butt state after winding once by banding it in the shape of square or circle, etc. The prescribed position close to the both end faces of the regular sized material W is held with pressing as stationary electrodes 1a, 2a and mobile electrode 1b, 2b and a cooling jacket 6 is located as well inside a tank 3 rotating a supporting arm 5. The vicinity of the both end faces of the regular sized material W is then heated by passing the current for welding and the both end faces are subjected to a resistance flash butt welding. The rapid cooling and hardening are simultaneously performed by jetting from the jet port S of the jacket 6 the cooling fluid of the inside of the tank 8 by a pump 7. The annealing is then performed by raising the temp. of the welding zone of the ring member W with its electrification again.