| 摘要 |
<p>PURPOSE:To improve the residual stress in the weld zone of a welded structure when the structure is heated to subject the inside to tensile yielding and the outside to compression by a temp. distribution given in the axial direction, by locally heating a part close to the weld zone. CONSTITUTION:A restraining ring 8 is fixed in the vicinity of the weld zone of a welded pipe, and a heating element 1 is set at a distance from the weld line 2 to carry out heating. By this heating, local deformation shown by a solid line is caused in the weld zone. A broken line 9 shown the shape before the heating. As a result, tensile stress 10 in the axial direction is produced in the heat affected zone close to the weld zone on the inside of the pipe, and the stress 10 is converted into compressive stress 11 after cooling.</p> |
