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

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to heat-resistant chrome-nickel alloys of austenitic class and can be used in production of collectors of reaction tubes of high-temperature plants of hydrogen, methanol and ammonia. Heat-resistant alloy contains, wt%: carbon 0.05÷0.15; silicon 0.50÷1.50; manganese 0.50÷1.50; chromium 19÷23; nickel 30÷33; niobium 0.70÷1.60; titanium 0.005÷0.10; zirconium 0.005÷0.15; tungsten 0.005÷0.10; lanthanum 0.005÷0.10; cobalt 0.0005÷0.10; molybdenum ≤0.10; sulfur ≤0.03; phosphorus ≤0.03; lead ≤0.01; tin + arsenic + zinc + antimony ≤0.02; nitrogen ≤0.05; copper ≤0.1; iron – balance. Alloy has a structure consisting of an austenite matrix and Cr_(22÷56)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 (91÷95):( 3÷8):( 1÷3).

EFFECT: providing uniform distribution of secondary carbides and intermetallides in austenite matrix – this enables to avoid carbonisation during pyrolysis of hydrocarbons and formation of hot cracks during welding of reaction tubes; alloy is characterized by high heat resistance.

1 cl, 2 ex