HIGH-TEMPERATURE ALLOY Russian patent published in 2016 - IPC C22C30/00 C22C19/05 

FIELD: metallurgy.

SUBSTANCE: invention relates to a low carbon austenitic chromium-nickel alloy, and can be used for making sewers and reaction tubes with gas processing installations operating modes at a temperature of 700÷980 °C and pressures up to 50 atm. Heat resistant alloy contains, wt%: carbon 0.06÷0.14; chrome 20.5÷23.5; silicon ≤ 1.05; manganese ≤ 1.05; vanadium 0.0005÷0.05; tungsten 0.0005÷0.05; titanium ≤ 0.55, aluminium - 0.75÷1.45; boron ≤ 0.006; yttrium > 0÷0.001; oxygen > 0.0005÷0.028; hydrogen > 0.0005÷0.0025; nitrogen > 0.0005÷0.095; sulphur ≤ 0.015; phosphorus ≤ 0.025; lead ≤ 0.009; tin ≤ 0.009; arsenic ≤ 0.009; zinc ≤ 0.009; antimony ≤ 0.009; molybdenum 8.2÷10.05; cobalt 10.5÷15.5; copper - ≤ 0.45; iron ≤ 3.0; nickel - balance when the following conditions are satisfied, wt%: (Cr_E/Ni_E) ≥ 0.51 wherein Cr_E - equivalent of chromium; Ni_E - equivalent of nickel; Cr_E=Cr+2×Al+3×Ti+V+Mo+1.6×Si+W; Ni_E=Ni+32×C+0.6×Mn+Co+22×N+Cu. For total content of sulphur and phosphorus, following condition is satisfied (S + P) ≤ 0.025 wt%.

EFFECT: increased structural stability of alloy in process of ageing, as well as reduced tendency to formation of hot cracks during welding.

2 cl