| abstract |
The present invention provides a method for producing a stainless steel pipe containing 15.5 to 18% Cr and having excellent toughness even when large and thick. SOLUTION: The above manufacturing method is, in mass%, C: 0.06% or less, Si: 1.0% or less, Mn: 0.05-2%, P: 0.05% or less, S: 0.00. 005% or less, Cr: 15.5 to 18.0%, Mo: 1.0 to 3.5%, Cu: 0.2 to 3.5%, Ni: 2.5 to 7.0%, Al: 0.001-0.1%, N: 0.06% or less, O: 0.01% or less, with the balance being hot-worked steel material composed of Fe and impurities, outer diameter 120mm or more, wall thickness It comprises a step of forming a blank tube of 13 mm or more, a step of quenching the blank tube from 850 to 1050 ° C., and a step of tempering the blank tube after quenching, and the tempering step holds the blank tube at 500 to 650 ° C. And the holding tube is cooled, and the average cooling rate in the temperature range of 500 to 400 ° C. is set to 10 ° C./min or more. And a step. [Selection] Figure 1 |