Composition

• Nickel (Ni): 38% - 46%
• Chromium (Cr): 19.5% - 23.5%
• Iron (Fe): 22% minimum
• Molybdenum (Mo): 2.5% - 3.5%
• Copper (Cu): 1.5% - 3%
• Titanium (Ti): 0.6% - 1.2%
• Small amounts of manganese, silicon, carbon, sulfur, and aluminium.

Properties

• Density: Approximately 8.14 g/cm³
• Melting Point: 1370°C - 1400°C (2500°F - 2550°F)
• Excellent corrosion resistance in both reducing and oxidizing environments.
• Good resistance to chloride-ion stress-corrosion cracking.
• Maintains good mechanical properties at both high and low temperatures.

Forging Details for Circles/Rings

• Forging Temperature Range: Typically forged at temperatures ranging from 870°C to 1180°C (1600°F to 2160°F).
• Forging of Incoloy 825 should be followed by a suitable heat treatment process to achieve optimal mechanical properties and corrosion resistance.
• Heat Treatment: After forging, Incoloy 825 can be annealed by heating at 940°C (1725°F) followed by cooling to enhance its ductility and to relieve internal stresses.
• Machinability: While Incoloy 825 can be machined, its work-hardening rate and alloying elements mean it may require slower speeds, more power, and better tooling than simpler steels.

Applications

• Chemical Processing: Used in reactors, columns, and piping for the processing of phosphoric and sulfuric acids.
• Oil and Gas: Piping, valves, and other components exposed to corrosive offshore and sour gas environments.
• Pollution Control Equipment: Flue gas desulfurization systems and scrubbers.
• Marine: Propeller shafts, seawater piping systems, and heat exchangers.

Standards and Specifications

• ASTM B425: Specification for rod and bar.
• ASTM B564: Specification for nickel alloy forgings.
• ASTM B423: Specification for seamless pipe and tube.
  These standards specify requirements for chemical composition, mechanical properties, heat treatment, and testing methods for Incoloy 825.