HEAT-RESISTANT ALLOY BASED ON NICKEL, ARTICLE MADE FROM IT, AND METHOD FOR HEAT TREATMENT OF ARTICLE Russian patent published in 2024 - IPC C22C19/05 C22F1/10 

FIELD: metallurgy.

SUBSTANCE: heat-resistant nickel-based alloy contains, wt.%: aluminium 5.7-6.3, tantalum 4.0-5.2, molybdenum 3.5-4.5, tungsten 3.2-5.2, rhenium 5.6-6.5, chrome 2.1-3.3, cobalt 5.0-7.0, cerium 0.001-0.02, lanthanum 0.002-0.1, yttrium 0.002-0.02, carbon 0.002-0.02, boron 0.0004-0.004, neodymium 0.0005-0.01, ruthenium 3.0-5.0, silicon 0.008-0.2, nickel – balance. Also disclosed is an article made from said alloy, having a monocrystalline structure. Method of heat treatment of article includes homogenizing annealing in range between temperature of complete dissolution of hardening γ'-phase T_f.d. and temperature of local melting of eutectic precipitates (γ+γ') T_l.m., two-stage aging and subsequent cooling. Before homogenizing annealing, the article is subjected to preliminary three-step annealing, wherein at the first step the article is heated to temperature of 690-710 °C and held at this temperature for 3.5-4.5 hours, followed by cooling, at the second stage, the article is heated to temperature of 1295-1305 °C and held at this temperature for 1.5-2.5 hours, at the third stage, the product is heated to temperature of 1330-1340 °C and held at this temperature for 1.5-2.5 hours, wherein the rate of heating the article between the first and second stages of the preliminary three-step annealing is not more than 20 °C/min, rate of heating the article between the second and third stages of preliminary three-stage annealing and between the third stage of preliminary three-stage annealing and homogenizing annealing is not more than 2 °C/min.

EFFECT: higher heat resistance at temperature of 1100 °C, low-cycle fatigue (LCF) resistance at temperature of 750 °C and long-term strength at temperature of 1200 °C of alloy based on nickel and articles made from it, as well as increased yield of suitable alloy and articles made from it.

3 cl, 3 tbl, 3 ex