HEAT TREATING DEVICE OF METALLIC ROD MATERIAL HAVING DIFFERENT WALL THICKNESSES

摘要

PURPOSE:To perform an efficient and uniform heat treatment of a steel pipe, etc. provided with thick-wall parts at both ends by moving two annular inductors for the thick-walled parts and normal part with respect to the metallic rod material having different wall thicknesses and heating and cooling the two parts. CONSTITUTION:An inductor 21 for a thick-walled part is placed on the outside circumference in the thick-walled part 1a at the end of a steel pipe 1, etc. and is heated to a prescribed temp. The inductor 21 is moved upward and cooling water is ejected from the nozzle of a jacket 31 to heat-treat uniformly the part 1a. The power supply to the inductor 21 is stopped and while an inductor 41 for a normal part is moved upward, the inductor is heated and the cooling water is ejected from the nozzle of a jacket 50 to heat-treat continuously the normal part. When the inductor 41 arrives at the prescribed position of the normal part 1c, the heat treatment by the inductor 21 standing by on the outside circumference of the upper thick-walled part 1b is started. Both ends of the steel pipe 1, etc. are kept supported by pipe end supporting members 2, 3 in this stage.