Incoloy 825 is a nickel-base alloy generally similar to Alloy 20 in aqueous corrosion. It has useful resistance to boiling sulfuric acid up to 40% concentration, to 60% concentration at 176°F and in all concentrations to 150°F. Alloy 825 is stabilized annealed at the mill to resist intergranular corrosion as-welded. If exposed for long times to the sensitive temperature range 1200-1400°F the alloy may exhibit severe intergranular corrosion in certain very aggressive environments.


825 Pipe, 825 Plate, 825 Sheet, 825 Weld Wire

Common Trade Names

Alloy 825, Incoloy 825, Inconel 825


  • Excellent resistance to sulfuric and phosphoric acids
  • Resists intergranular corrosion in the as-welded condition
  • Practical immunity to chloride stress corrosion cracking (SCC)
  • Resists polythionic acid SCC


  • Valves
  • Phosphoric acid production
  • Chemical process vessels
  • Catalytic cracking units