| 摘要 |
<p>A steel pipe excellent in steam resistance oxidation characteristics and its manufacturing method. The steel pipe excellent in steam resistance oxidation characteristics contains 9-28 mass% of Cr, characterized in that the surface area in the pipe subjected to shot peening is 70% or more by visual coverage. In the manufacturing method of the steel pipe, when the surface in the pipe is subjected to shot peening by moving a shot nozzle relatively in the longitudinal direction of pipe while the steel pipe is rotated relatively, shot flow rate is set at 5 kg/min or above, shot peening is performed under conditions satisfying a following expression (a) and the area subjected to shot peening (visual coverage) is 70% or above. L x r/v=1.5...(a) where, L: length over which shot particles ejected from a nozzle strike the inner circumferential surface of the pipe (mm) r: rotational speed of steel pile (rpm) v: feeding speed of the nozzle in the longitudinal direction of the steel pipe (mm/min).</p> |
