AUSTENITIC HEAT-RESISTANT ALLOY

摘要

Disclosed is an austenitic heat-resistant alloy, which contains 0.15% or less of C, 2% or less of Si, 3% or less of Mn, 40-60% of Ni, 0.03-25% of Co, 15% or more but less than 28% of Cr, 12% or less of Mo and/or less than 4% of W with the total being 0.1-12%, 0.001-0.1% of Nd, 0.0005-0.006% of B, 0.03% or less of N, 0.03% or less of O, and one or more selected from among 3% or less of Al, 3% or less of Ti and 3% or less of Nb, with the balance made up of Fe and impurities that include 0.03% or less of P and 0.01% or less of S, and which satisfies 1 = 4 × Al + 2 × Ti + Nb = 12 and P + 0.2 × Cr × B < 0.035. The austenitic heat-resistant alloy has both excellent weld cracking resistance and excellent toughness in the HAZ, while exhibiting excellent creep strength at high temperatures. Consequently, the austenitic heat-resistant alloy is suitable for use as a material for high-temperature devices such as a boiler for power generation and a chemical industry plant. The austenitic heat-resistant alloy may contain one or more elements selected from among Ca, Mg, La, Ce, Ta, Hf and Zr in a specific amount.