| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress occurrence of any crack in the vicinity of a weld part of a flange part. <P>SOLUTION: A tubular body includes a tube body made of ferritic stainless steel, a flange part, and a weld part. The flange part is an annular part formed by bending an end in the axial direction of the tube body outwardly in the radial direction. The weld part is provided over the tube body and the flange part. The relationship between the Ni equivalent n and the yield stressσis expressed byσ=an+b (where, a and b are constant) when Ni is added to ferritic stainless steel. In this case, the Ni equivalent p at the weld part and the ratio of the thickness of the weld part to the thickness of the tube body is set so that the point (p, q) in the x-y coordinate is located within an area surrounded by lines L1-L4 indicating x=(300-b)/a, x=(355-b)/a, y=355/(ax+b) and y=300/(ax+b). <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
