| 摘要 |
PURPOSE:To decrease strains caused by hardening, and uneven hardening, at the time of hardening a steel pipe, by rolling the steel pipe on a horizontal conveying table and charging the same from its end into a hardening vessel. CONSTITUTION:A heated steel pipe W is placed on a horizontal conveying table 2 by a kicker 3. In this case, rotationg motion is given to the steel pipe W by the kicker 3 so that the steel pipe W rolls on the conveying table 2. The steel pipe W rolls on the table 2, falls by gravity from the end 5 and seats in the predetermined position on the cradle 6 in a water tank 1. Clamps 8 are mounted to the steel pipe W, and cooling water is sprayed to th inside and outside surface of the sttel pipe W from cooling water nozzles 7a-7c, whereby it is hardened. With this method, the steel pipe W falls by gravity within the perpendicular plane without receiving any restraint and arrives at the predetermined position in the water tank at the shortest time and distance; therefore, the occurrence of uneven cooling decreases considerably and the annealing strains decrease as well. |
