| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reasonably implement dimensional stabilization heat treatment for a metallic structure, which serves as improvement of a remaining tensile stress in the surface of the structure into a compressive stress. <P>SOLUTION: This heat-treatment method comprises heating a welded structure made of an austenitic stainless steel or a nickel-based alloy in such a temperature gradient as not to cause deformation in the welded structure, as shown in a temperature history curve 7 in the dimensional stabilization heat treatment; holding it at 400°C which is a specific temperature necessary for stabilizing the dimension; subsequently, starting cooling of the welded structure in such a temperature gradient as not to cause deformation in the welded structure, as shown in the temperature history curve 7; and in the cooling step, forcibly cooling the surface of the welded structure at 300°C or lower, in which the strength of the base metal of the structure is enhanced, as shown in the temperature history curve 8 in the surface forced-cooling heat treatment, to impart a compressive stress to the surface of the welded structure. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
