Patent ID: 8241439

Claim:
The Ni—Cr alloy tube having a chemical composition consisting of by mass C: 0.15% or less, Si: 1.00% or less, Mn: 2.0% or less, P: 0.030% or less, Sulfur: 0.030% or less, Cr: 10.0 to 45.0%, Fe: 15.0% or less, Ti: 0.5% or less and Al: 2.00% or less, with the balance of Ni and impurities, wherein the difference between uniform lattice strains of the surface layer thereof satisfies the following formulas (1) and (2): S≦0.002 (1) S=D 500 −D ≦200 (2) wherein the meanings of the individual symbols in the above described formulas are as follows; S: the difference between uniform lattice strains (Å) of the surface layer, D 500 : the {111} interplanar spacing (Å) at a depth of 500 nm from the material surface, and D ≦200 : the average value of the {111} interplanar spacings (Å) at the depth of 200 nm or less from the material surface.