HEAT-RESISTANT ALLOY Russian patent published in 2019 - IPC C22C19/05 C22C30/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly to heat-resistant chrome-nickel alloys of austenitic class with intermetallic hardening, and can be used in production of reaction tubes for ammonia and methanol units with operating temperatures of 800–950 °C and pressure of 2.5–5 MPa and oil and gas processing plants with operation modes from 950 to 1,160 °C and pressure up to 0.7 MPa. Heat-resistant alloy contains, wt%: carbon 0.30÷0.50; silicon 0.8÷1.60; manganese 0.9÷1.50; chromium 24.0÷27.0; nickel 33.0÷36.0; niobium 0.8÷1.90; titanium 0.11÷0.25; cerium >0÷0.05; lanthanum 0.0005÷0.10; zirconium 0.0005÷0.10; tungsten 0.11÷0.25; aluminum 0.0005÷0.10; vanadium 0.0005÷0.20; cobalt 0.0005÷0.10; molybdenum 0.0005÷0.10; sulfur ≤0.02; phosphorus ≤0.02; lead ≤0.007; tin ≤0.006; arsenic ≤0.006; zinc ≤0.006; stibium ≤0.007; nitrogen ≤0.01; copper ≤0.1; iron – balance. Alloy has an austenitic structure consisting of an austenite matrix and Cr_(22÷52)Fe_(4÷7)Ni and Nb_(25÷35)Cr₍₂._5÷3.5)(FeNiTi)_(0.9÷1.1) intermetallides distributed therein at weight ratio of austenitic matrix and intermetallides (90÷95):(3÷8):(1÷3).

EFFECT: higher degree of homogeneity of secondary carbides in alloy structure; alloy is characterized by high values of heat resistance.

1 cl, 2 ex