Patent ID: 11807910

Abstract:
Provided is an austenitic alloy pipe, which has high yield strength, excellent SCC resistance, suppressed strength anisotropy, and high detectability in ultrasonic flaw detection. The austenitic alloy pipe according to the present embodiment has a chemical composition consisting of: in mass %, C: 0.004 to 0.030%, Si: 1.00% or less, Mn: 0.30 to 2.00%, P: 0.030 or less, S: 0.0020% or less, Al: 0.001 to 0.100%, Cu: 0.50 to 1.50%, Ni: 25.00 to 55.00%, Cr: 20.00 to 30.00%, Mo: 2.00 to 10.00%, and N: 0.005 to 0.100%, with the balance being Fe and impurities. A grain size number of austenite crystal grain is 2.0 to 7.0 and a mixed grain ratio is not more than 5%. Tensile YS is not less than 758 MPa, compressive YS/tensile YS is 0.85 to 1.10, and an outer diameter is not less than 170 mm.