A Ni—Cr alloy material has a chemical composition that consists of; Si: 0.01 to 0.5%, Mn: 0.01 to less than 1.0%, Cu: 0.01 to less than 1.0%, Ni: 48 to less than 55%, Cr: 22 to 28%, Mo: 5.6 to less than 7.0%, N: 0.04 to 0.16%, sol.Al: 0.03 to 0.20%, REM: 0.01 to 0.074%, W: 0% or more and less than 8.0%, Co: 0 to 2.0%; one or more of Ca and Mg: 0.0003 to 0.01% in total, and one or more of Ti, Nb, Zr, and V: 0 to 0.5% in total, the balance thereof being Fe and impurities. The impurities include C £ 0.03%, P £ 0.03%, S £ 0.001%, and O £ 0.01%. The dislocation density r of the Ni—Cr alloy material expressed in m−2 satisfies a formula [7.0′1015£r£2.7′1016−2.67′1017′REM].