Alloy pipe and method for producing same

A method for producing an alloy pipe comprising, as a component composition, in terms of % by mass, Cr:

• 11.5-35.0% Ni:
• 23.0-60.0%, and Mo:
• 0.5-17.0%, the alloy pipe being a steel alloy pipe having an austenitic phase as a microstructure, having a Mo concentration (% by mass) in a grain boundary of the austenitic phase that is 4.0 times or less than a Mo concentration (% by mass) within grains of the austenitic phase, and having a tensile yield strength in a pipe axial direction of 689 MPa or more and a ratio of compressive yield strength in a pipe axial direction to tensile yield strength in the pipe axial direction of 0.85 to 1.15,
• the method comprising, after a solid solution heat treatment, performing cold bending and unbending work in a pipe circumferential direction,
• wherein a maximum achieving temperature of a worked material after the cold bending and unbending work is 300° C. or less, and
• wherein the cold bending and unbending work is performed such that a rolling management value falls within a predetermined range, the rolling management value obtained by multiplying (1−Dmin/Di)×100 by ti/Di, wherein Di is an initial diameter of the alloy pipe, Dmin is a minimum diameter of the alloy pipe during the cold bending and unbending, and ti is an initial wall thickness of the alloy pipe, and wherein the predetermined range is 0.5 to 3.0.