| 摘要 |
PURPOSE:To relieve weld of its residual stress to approx zero by providing a radiative heat insulator in the inside of apparatus in the neighborhood of welding coupler in an apparatus in which a heating element is provided in the inside of cylindrical structure in order to relieve its welding residual stress. CONSTITUTION:Using the heat insulator 6 and the heating element 4, a cylindrical structure is formed into a furnace body, and then the radiative heat insulator 7 is provided in the neighborhood of the welding coupler inside. When local annealing is made under such a condition, the amount of incoming heat is lessened to an extreme extent and thus the temperature at the position where the radiative heat insulator is located is lowered from its both ends, thus relieving the weld of its residual stress. The apparatus is effectively applicable to chemical plants under severe corrosive environments. |
