To produce a heat resistant alloy which has excellent strength and toughness, and can exhibit excellent characteristics over a long period even in a severe vapor environment where temperature and pressure are increased, and heat resistant alloy parts.
The heat resistant alloy having excellent strength and toughness has a composition containing, by weight, 50-55% Ni, 17 to 21% Cr, Nb or Nb and Ta by 4.75 to 5.5% in total, 2.8 to 3.3% Mo, 0.65 to 1.15% Ti, 0.2 to 0.8% Al, ≤1.0% Co, ≤0.08% C, ≤0.35% Mn, ≤0.35% Si, ≤0.015% P, ≤0.006% B and ≤0.3% Cu, and the balance Fe with inevitable impurities. Its 0.2% cold proof stress at normal temperature after solution heat treatment and subsequent aging heat treatment is ≥1,034 MPa, and Charpy impact value is ≥50 J/cm2. The heat resistant alloy parts use this alloy.
TSUBOTA MOTOJI
TSUDA YOICHI
YAMADA MASAYUKI
