Acid and Alkali Resistant Ni-Cr-Mo-Cu Alloys with Critical Contents of Chromium and Copper

摘要

A nickel-chromium-molybdenum-copper alloy resistant to 70% sulfuric acid at 93° C. and 50% sodium hydroxide at 121° C. for acid and alkali neutralization in the field of waste management; the alloy contains, in weight percent, 27 to 33 chromium, 4.9 to 7.8 molybdenum, 3.1 to 6.0 wt. % copper (when chromium is between 30 and 33 wt. %) or 4.7 to 6.0 wt. % copper (when chromium is between 27 and 29.9 wt. %), up to 3.0 iron, 0.3 to 1.0 manganese, 0.1 to 0.5 aluminum, 0.1 to 0.8 silicon, 0.01 to 0.11 carbon, up to 0.13 nitrogen, up to 0.05 magnesium, up to 0.05 rare earth elements, with a balance of nickel and impurities. Titanium or another MC carbide former can be added to enhance thermal stability of the alloy.

主权项

1. A nickel-chromium-molybdenum-copper alloy resistant to sulfuric acid, having a corrosion rate of less than 0.45 mm/y in 70% sulfuric acid at 93° C. and resistant to sodium hydroxide, having a maximum internal attack corresponding to corrosion rate of less than 0.45 mm/y in 50% sodium hydroxide at 121° C., consisting essentially of:
30 to 33 wt. % chromium 4.9 to 7.8 wt. % molybdenum 3.1 to 6.0 wt. % copper up to 3.0 wt. % iron 0.3 to 1.0 wt. % manganese 0.1 to 0.5 wt. % aluminum 0.1 to 0.8 wt. % silicon 0.01 to 0.11 wt. % carbon up to 0.13 wt. % nitrogen up to 0.05 wt. % magnesium up to 0.05 wt. % rare earth elements up to 0.56 wt. % titanium up to 1.12 wt. % niobium up to 2.24 wt. % tantalum up to 2.24 wt. % hafnium with a balance of nickel and impurities.