| 摘要 |
PURPOSE: To assemble a welded duct assembly which has substantially no strain in a heat affected zone by welding, which gives a negative effect upon a fatigue life of the duct assembly, and is precisely dimensioned and welded. CONSTITUTION: A tubing is made from a flat metal or an alloy, and the tubing is annealed while applying a radial pressure on the surface of the tubing, and a duct assembly is assembled by welding an end of the tubing with such an element as a fitting, a spacer, a connector, a flange, or another tubing which was similarly processed. The annealing process includes a processing of the tubing with which a residual stress resulting from making the tubing is relieved. |
