HEAT-RESISTANT ALLOY OF AUSTENITE STRUCTURE WITH INTERMETALLIC HARDENING Russian patent published in 2019 - IPC C22C30/00 C22C19/05 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular to heat-resistant austenitic alloy with intermetallic hardening, and can be used in production of reaction tubes for ammonia and methanol units with working temperatures of 850–950 °C and pressure of 2.5–5 MPa and oil and gas processing plants with operating modes from 1,000 to 1,160 °C and pressure up to 0.7 MPa. Heat-resistant chromium-nickel alloy contains, wt%: carbon 0.35÷0.45; silicon 1.4÷2.0; manganese 0.8÷1.55; chrome 34÷36; nickel 43÷47; titanium 0.26÷0.50; zirconium <0.1; cerium 0.005÷0.10; lanthanum 0.005÷0.10; scandium 0.005÷0.10; cobalt 0.005÷0.10; aluminum 0.001÷0.05; sulfur ≤0.025; phosphorus ≤0.025; lead ≤0.007; tin ≤0.007; arsenic ≤0.007; zinc ≤0.007; antimony ≤0.007; nitrogen ≤0.01; copper ≤0.2; iron – balance. Alloy has structure consisting of austenite matrix and Cr_(25÷60)Fe_(3÷7)Ni and Nb_(26÷34)Cr_(2.6÷3.4)(FeNiTi)_(0.9÷1.1) intermetallides distributed therein at weight ratio of austenitic matrix and intermetallides (88÷94):(4÷10):(1÷3).

EFFECT: alloy is characterized by high mechanical properties, including heat resistance; there are no cracks in welding pipes made from said alloy.

1 cl, 2 dwg