Copper-containing Ni-Cr-Mo alloys

A corrosion resistant nickel-chromium-molybdenum-copper alloy consisting essentially of about:

• Chromium:
• 22.0 to 24.5 wt. %
• Molybdenum:
• 15.0 to 17.0 wt. %
• Copper:
• 1.3 to 1.9 wt. %
• Iron:
• Up to 3.0 wt. %
• Silicon:
• Up to 0.08 wt. %
• Manganese:
• Up to 0.5 wt. %
• Cobalt:
• Up to 2.0 wt. %
• Aluminum:
• Up to 0.5 wt. %
• Carbon:
• Up to 0.01 wt. %
• with the balance nickel and inevitable impurities and trace amounts of at least one of magnesium and calcium from deoxidation.

A process for improving the corrosion resistance of nickel base alloys, having about 22 to 25 wt. percent chromium and 14 to 18 wt. percent molybdenum, and less than about 5% iron, comprising the steps of adding about 1.3 to 1.9 wt. percent copper to the base composition to form an alloy composition consisting essentially of:

• Chromium:
• about 22.5 to 23.3 wt. %
• Molybdenum:
• about 14.6 to 16.6 wt. %
• Copper:
• about 1.0 to 3.1 wt. %
• Iron:
• about 0.9 to 4.2 wt. %
• Silicon:
• about 0.02 to 0.08 wt. %
• Manganese:
• up to 0.5 wt. %
• Cobalt:
• about 0.1 to 0.5 wt. %
• Aluminum:
• about 0.19 to 0.41 wt. %
• Carbon:
• up to b 0.01 wt. %
• Tungsten:
• up to 0.27 wt. %
• with the balance nickel and inevitable impurities;
• and
• then forming the resulting alloy into products.

A nickel-chromium-molybdenum-copper corrosion resistant wrought product consisting essentially of, in weight percent, about:

• Chromium:
• 22.35 to 23.65%;
• Molybdenum:
• 15.35 to 16.65%;
• Copper:
• 1.4 to 1.8%;
• Iron:
• 0.3 to 1.5%;
• Silicon:
• Up to 0.05%;
• Manganese:
• 0.10 to 0.30%;
• Cobalt:
• Up to 1.95%;
• Aluminum:
• 0.15 to 0.30%;
• Carbon:
• Up to 0.007%;
• Nitrogen:
• Up to 0.06%;
• Tungsten:
• Up to 0.5%;
• Carbide forming elements:
• Up to 0.35% in total;
• and
• with a balance of nickel and inevitable impurities, characterized by having a corrosion rate of less than 30 mpy when tested in boiling 2.5% HCl acid.