| 摘要 |
The pipe end correction method of a seamless pipe for correcting an inner diameter of pipe end of a seamless pipe made of a high Cr stainless steel containing 8 to 35 mass% Cr, and 0.1 to 10 mass% Ni includes: a pipe end correction step, following hot tube-making and heat treatment, of forcing a plug into the inside of pipe end portion of the seamless pipe for inner diameter correction so as to expand the pipe end portion while oxide scale remains accumulated on an inner surface of the pipe end portion of the seamless pipe, the oxide scale being generated during the tube-making or the heat treatment; and a lubricant film forming step, prior to the pipe end correction step, of applying lubricant at least either on the inner surface of the pipe end portion of the seamless pipe or on a surface of the plug so as to form a lubricant film thereon. This makes it possible to prevent seizure flaws from being generated on the inner surface of the pipe end portion in the case of producing the seamless pipe of the high Cr stainless steel. |
