Austenitic stainless alloy material

Abstract

An austenitic stainless alloy material that has excellent creep strength and excellent stress relaxation cracking resistance is provided. An austenitic stainless alloy material according to the present disclosure contains, in mass %, C: 0.03 to 0.12%, Si: 0.05 to 2.00%, Mn: 0.05 to 3.00%, P: 0.03% or less, S: 0.010% or less, Ni: 18.0 to less than 25.0%, Cr: 22.0 to less than 30.0%, Co: 0.04 to 0.80%, Ti: 0.002 to 0.010%, Nb: 0.1 to 1.0%, V: 0.01 to 1.00%, Al: 0.001 to less than 0.030%, and N: 0.10 to 0.35%. The number density of precipitates having an equivalent circular diameter of 0.5 to 2.0 μm is 5000 pieces/mm 2 or more.

1 . An austenitic stainless alloy material consisting of, in mass %,
 C: 0.03 to 0.12%,   Si: 0.05 to 2.00%,   Mn: 0.05 to 3.00%,   P: 0.03% or less,   S: 0.010% or less,   Ni: 18.0 to less than 25.0%,   Cr: 22.0 to less than 30.0%,   Co: 0.04 to 0.80%,   Ti: 0.002 to 0.010%,   Nb: 0.1 to 1.0%,   V: 0.01 to 1.00%,   Al: 0.001 to less than 0.030%,   N: 0.10 to 0.35%,   Mo: 0 to 1.00%,   W: 0 to 1.00%,   B: 0 to 0.010%, and   Ca: 0 to 0.0100%,   with the balance being Fe and impurities,   wherein a number density of precipitates having an equivalent circular diameter of 0.5 to 2.0 μm is 5000 pieces/mm 2  or more.   
     
     
         2 . The austenitic stainless alloy material according to  claim 1 , containing one kind of element or more selected from a group consisting of:
 Mo: 0.01 to 1.00%,   W: 0.01 to 1.00%,   B: 0.001 to 0.010%, and   Ca: 0.0001 to 0.0100%.