| 摘要 |
PURPOSE:To enhance the endurance of a stainless steel pipe by making the cooling rate of the inside of the pipe higher than that of the outside in the quenching stage of solution heat-treatment to leave larger compressive stress at the inside. CONSTITUTION:A stainless steel pipe 1 is mounted on a support 2, a spray device is set in the pipe 1, and water is sprayed 4 on the inner wall of the pipe 1 from the nozzles 3 of the device. Accordingly, the inside of the pipe 1 is cooled more rapidly than the outside. By carrying out the quenching stage of solution heat-treatment as mentioned above, larger residual compressive stress is distributed at the inside of the pipe after solution heat-treatment over a large thickness range. |
