Is incoloy corrosion resistant?
In general, high nickel content alloys do have excellent resistance to many forms of corrosion. However, in more harsh environments-especially at high temperatures-some may struggle to maintain the same excellent performance. The Nickel Institute estimates that an increase in temperature of just 10 degrees can increase corrosion rates by up to 12 times, demonstrating how important it is to select an alloy with properties suitable for the intended application.
Oxidation, carburization and sulfidation can all occur in high temperature environments, increasing the risk of surface pitting, stress corrosion cracking and sulfide diffusion. Increasingly high process temperatures are under intense pressure to operate at higher efficiencies, creating a need for many different industries to find an affordable solution that maintains strong corrosion resistance even at high temperatures.
Fortunately, there is a solution: INCOLOY Alloy 800, which has successfully set the industry standard for strong, versatile nickel alloys with unparalleled corrosion resistance even at high temperatures.
What is Incoloy 800 alloy?
INCOLOY 800 is a form of INCOLOY alloy developed by Specialty Metals. It combines nickel, chromium and iron with trace amounts of other metals and is known for its strength, durability and resistance to oxidation, carburization and sulfide corrosion.
To be classified as INCOLOY 800, the alloy must consist of:
30-35% Nickel
19-23% Chromium
39.5%+Iron
0.15-0.6% aluminum
0.15-06.% Titanium
Carbon content up to 0.10
INCOLOY Alloy 800 was first developed in the 1950s. Today it is used not only as an alloy in its own right, but also as the basis for many other alloys in the INCOLOY 800 series. Some of these alloys offer enhanced corrosion resistance, which we will explore in more detail later in this article.
High performance alloy
INCOLOY Alloy 800 has a reputation as a high-performance superalloy capable of resisting corrosion in some of the harshest environments. It all depends on its ingredients. INCOLOY Alloy 800's high nickel content provides good resistance to sulfidation. The iron reduces the risk of internal oxidation, while the chromium provides excellent resistance to oxidation and general corrosion. Its critical chemical balance makes it excellent in resisting many types of corrosion. Demonstrate excellent performance. corrosion. This includes scaling and stress corrosion cracking, particularly chloride stress corrosion due to the formation of metal chlorides.
In many cases, the corrosion rate of INCOLOY Alloy 800 has been shown to start very quickly and then moderate to a slower, more consistent rate. This is because polarization resistance increases with prolonged exposure. Ultimately, this allows INCOLOY Alloy 800 to corrode at a much slower rate than Stainless Steel 304, making it a better choice for certain applications.
Research has found that INCOLOY Alloy 800 exhibits high corrosion resistance when exposed to molten carbonates, molten eutectic salt deposits, hydrogen peroxide and hydrogen chloride in moist air. While research in this area may be limited, it has also been found to be highly resistant to sulfuric acid, with a reported corrosion rate of only 0.51 mm/year (20mpy) when exposed to 5% sulfuric acid at a temperature of 50 degrees. ) Research conducted by the Nickel Institute.
Application areas
Because INCOLOY Alloy 800 has such significant corrosion resistance, especially at higher temperatures, it is most commonly used in applications where high temperatures are common, such as industrial incinerators, furnace tubes, heat treatment equipment, and electric heating elements. It can even be used in steam generator piping and is commonly found in paper mills.
Overall, INCOLOY Alloy 800 is an excellent choice for environments up to 816 degrees. If a high level of corrosion resistance is required at higher temperatures, other alloys in the INCOLOY 800 series can be used as alternatives, such as 800H, 800HT or even INCOLOY 825.
