Incoloy Alloy Overview

Incoloy alloys are a series of high-performance, iron-nickel-chromium alloys designed for use in high-temperature and corrosion-resistant applications. These alloys are primarily composed of nickel and chromium, with varying additions of other elements like iron, molybdenum, and copper. Incoloy alloys are well-regarded for their excellent resistance to oxidation, corrosion, and high-temperature stability. They are commonly used in industries such as chemical processing, power generation, aerospace, and marine engineering.

Key Incoloy Alloys: 800, 803, and 825

Incoloy 800

• Composition: Primarily consists of 32-38% nickel, 19-23% chromium, and 39-45% iron.
• Characteristics:
  • Excellent resistance to oxidation and carburization at high temperatures.
  • Good mechanical properties at elevated temperatures (up to 1,600°F / 870°C).
  • Good weldability and formability.
  • Stable structure even in harsh conditions.
• Applications:
  • Commonly used in furnace components, heat exchangers, chemical reactors, and boiler tubes.
  • Ideal for applications in the nuclear and petrochemical industries.

Incoloy 803

• Composition: Similar to Incoloy 800, but with an increased addition of molybdenum and niobium.
• Characteristics:
  • Enhanced resistance to creep and stress rupture at high temperatures.
  • Improved oxidation resistance compared to Incoloy 800.
  • Excellent resistance to hydrogen attack and corrosion in reducing atmospheres.
• Applications:
  • Mainly used in gas turbines, superheater tubes, and heat exchangers.
  • Ideal for power generation and high-stress environments where better long-term performance is needed.

Incoloy 825

• Composition: Contains approximately 38-46% nickel, 19.5-23.5% chromium, and 2.5-3.5% molybdenum, along with small amounts of titanium and copper.
• Characteristics:
  • Superior corrosion resistance to a wide range of acidic environments, including sulfuric, phosphoric, and nitric acids.
  • Excellent resistance to stress-corrosion cracking, pitting, and crevice corrosion.
  • Good weldability and formability.
  • High strength and resilience at elevated temperatures.
• Applications:
  • Widely used in chemical processing (reactors, piping, and heat exchangers).
  • Ideal for oil and gas applications, including offshore structures and desalination plants.
  • Suitable for environments with a combination of high temperature and corrosive materials.

Summary

Incoloy 800, 803, and 825 are high-performance alloys designed for extreme environments. Incoloy 800 excels in high-temperature strength and oxidation resistance, making it ideal for heat exchangers and chemical reactors. Incoloy 803 offers improved high-temperature creep resistance and is often used in gas turbines and superheater tubes. Incoloy 825 provides exceptional resistance to a wide range of corrosive environments, particularly acids, and is widely used in chemical processing and oil and gas industries. All three alloys offer excellent mechanical properties and high-temperature stability, making them essential in demanding industrial applications.