Inconel Alloy 625 VS Hastelloy Alloy C-276, performance comparison.

Shanghai Lion Metal Co., Ltd. Nickel-based Alloy Division

Inconel Alloy 625 and Hastelloy Alloy C-276 are both high-performance nickel-based alloys known for their excellent corrosion resistance in a wide range of aggressive environments. Here’s a comparison of their performance characteristics:

Corrosion Resistance:

  • Inconel Alloy 625:
  • Excellent resistance to a wide range of corrosive environments including acids, salts, and seawater.
  • Particularly strong resistance to crevice and pitting corrosion.
  • Hastelloy Alloy C-276:
  • Exceptional resistance to oxidizing and reducing environments.
  • Highly resistant to chloride-induced stress corrosion cracking and pitting.

Conclusion: While both alloys offer excellent corrosion resistance, Hastelloy C-276 is often preferred for applications involving harsh chemical environments and where resistance to localized corrosion is critical.

Temperature Resistance:

  • Inconel Alloy 625:
  • Good strength and oxidation resistance at elevated temperatures up to about 980°C (1800°F).
  • Hastelloy Alloy C-276:
  • Excellent high-temperature strength and oxidation resistance up to about 1040°C (1900°F).

Conclusion: Hastelloy C-276 generally offers better performance at higher temperatures compared to Inconel 625.

Mechanical Properties:

  • Inconel Alloy 625:
  • Good tensile, fatigue, and creep-rupture strengths at both room and elevated temperatures.
  • Retains its mechanical properties over a wide range of temperatures.
  • Hastelloy Alloy C-276:
  • High strength and toughness across a broad range of temperatures.
  • Maintains ductility after prolonged exposure to high temperatures.

Conclusion: Both alloys have strong mechanical properties suitable for demanding applications, with slight advantages depending on specific temperature ranges.

Weldability:

  • Inconel Alloy 625:
  • Generally good weldability using conventional welding techniques.
  • Minimal heat-affected zone (HAZ) cracking when proper welding practices are followed.
  • Hastelloy Alloy C-276:
  • Weldable using a variety of techniques, including gas tungsten arc (GTAW), gas metal arc (GMAW), and shielded metal arc (SMAW) welding.
  • Requires careful attention to pre- and post-weld heat treatments to avoid corrosion.

Conclusion: Both alloys are weldable, but Hastelloy C-276 may require more stringent welding procedures.

Applications:

  • Inconel Alloy 625:
  • Used in marine and aerospace applications, chemical processing equipment, and nuclear reactors.
  • Hastelloy Alloy C-276:
  • Widely used in chemical processing, pollution control, pulp and paper production, and waste treatment.

Conclusion: Hastelloy C-276 is often chosen for its superior corrosion resistance in aggressive chemical environments, while Inconel 625 finds applications where high strength and oxidation resistance are crucial.

Cost:

  • Inconel Alloy 625:
  • Generally more economical compared to Hastelloy C-276.
  • Hastelloy Alloy C-276:
  • Higher cost due to its superior corrosion resistance and broader applicability in severe environments.

Conclusion: Inconel 625 is more cost-effective, making it a preferred choice where the highest corrosion resistance of Hastelloy C-276 is not required.

Summary:

  • Inconel Alloy 625 is preferred for its good balance of strength, toughness, and corrosion resistance in less severe environments and at lower cost.
  • Hastelloy Alloy C-276 excels where exceptional corrosion resistance, particularly against chlorides and reducing acids, along with high-temperature strength, is essential despite its higher cost.

The choice between these alloys depends on specific application requirements, particularly the nature of the corrosive environment and operating temperatures.