HEAT-RESISTANT ALLOY Russian patent published in 2017 - IPC C22C30/00 C22C19/05 

FIELD: metallurgy.

SUBSTANCE: invention relates to heat resistant alloys, which can be used for manufacturing reaction tubes of ethylene production plants with operating conditions at temperature plus 900÷1160°C and pressure up to 6 atmospheres. The heat-resistant alloy contains, wt %: carbon 0.35÷0.45; silicon 1.60÷2.10; manganese 1.00÷1.50; chrome 34.0÷36.0; nickel 43.0÷47.0; titanium 0.05÷0.20; tungsten ≤0.25; vanadium 0.005÷0.10; zirconium 0.03÷0.12; cerium 0.005÷0.10; niobium 0.50÷1.20; sulfur ≤0.02; phosphorus ≤0.02; lead ≤0.007; tin ≤0.007; arsenic ≤0.007; zinc ≤0.007, antimony ≤0.007; nitrogen> 0.0005÷0.095; copper ≤0.2; yttrium >0÷0.001, aluminium >0÷0.05; hydrogen >0.0005÷0.0025; oxygen >0.0005÷0.028; iron is the rest; when the following conditions are satisfied, wt %: (Cr_E/ Ni_E)≥0.626, where Cr_E - equivalent of chromium; Ni_E - equivalent of nickel; Cr_E=Cr+2×Al+3×Ti+V+1.6×Si+0.6×Nb+W; Ni_E=Ni+32×C+0.6×Mn+Cu.

EFFECT: increase of structural stability of the alloy during ageing, reduction of alloy susceptibility to the formation of hot cracks when welding.

2 cl