REFRACTORY ALLOY Russian patent published in 2017 - IPC C22C38/50 C22C30/00 C22C19/05 

FIELD: metallurgy.

SUBSTANCE: invention relates to the use of an alloy for manufacturing of reaction tubes of ethylene, hydrogen, ammonia, carbon disulfide, methanol production units and with operating modes at the temperature 600÷1,200°C with and pressure up to 50 atm. The refractory alloy contains, by mass %: carbon ≤0.60; chrome 16.0÷29.0; nickel 8.0÷50.0; tungsten ≤6.0; niobium ≤2.0; zirconium 0.005÷0.20; yttrium 0.005÷0.15; beryllium ≤0.20; barium ≤0.35; calcium ≤0.25; cobalt ≤16; cerium ≤0.2; silicon ≤2.75; manganese ≤2.00; vanadium ≤0.2; magnesium ≤0.15; titanium ≤0.6; boron ≤0.015; aluminium ≤1.1; lanthanum 0.002÷0.030; neodymium 0.002÷0.010; praseodym 0.002÷0.010; hafnium 0.002÷0.5; rhenium 0.002÷0.5; tantalum 0.002÷0.5; iron is the rest; sulfur ≤0.04; phosphorus ≤0.04; lead ≤0.02; tin ≤0.02; arsenic ≤0.02; antimony ≤0.02; zinc ≤0.02; nitrogen >0.0005÷0.095; oxygen >0.0005÷0.028; hydrogen >0.0005÷0.0025; molybdenum ≤0.6; copper ≤1.1 under the following conditions, wt %: (Cr_E / Ni_E)≥0.506, where Cr_E is the equivalent of chromium; Ni_E is the equivalent of nickel; Cr_E=Cr+2×Al+3×Ti+V+Mo+1.6×Si+W+0.6×Nb; Ni_E=Ni+32×C+0.6×Mn+Co+22×N+Cu.

EFFECT: increased structural alloy stability during aging, lowered alloy propensity to hot cracking at welding.

3 cl