Hastelloy C22

Product Overview

Hastelloy C22 is a high-temperature, corrosion-resistant alloy containing a high percentage of elements like Cr and Mo, and features a single-phase austenitic microstructure, offering excellent corrosion resistance. It is a versatile nickel-chromium-molybdenum-tungsten alloy with superior overall corrosion resistance compared to other existing nickel-chromium-molybdenum alloys, including Hastelloy C276, C4, and 625 alloys. Hastelloy C22 exhibits excellent resistance to pitting, crevice, and stress corrosion cracking, along with good resistance to aqueous media, including mixtures of wet chlorine or oxidizing acids containing chloride ions.

The corrosion resistance of Hastelloy C22 alloy is due to the design of its chemical composition. Its main elements are nickel, chromium, and molybdenum, with a high nickel content exceeding 50%. The presence of nickel contributes to the alloy's excellent corrosion resistance, while molybdenum and chromium enhance its resistance, especially in oxidizing acids and chloride-containing media. Additionally, Hastelloy C22 alloy contains a certain proportion of tungsten, which serves to increase the hardness and strength of the alloy.

Chemical Composition

Nickel: Inventory Left

Chromium (Cr): 20-22.5%

Molybdenum (Mo): 12.5-14.5

Iron Fe: 2-6

Tungsten: 2.5-3.5

Cobalt (Co): ≤2.5

Carbon C: ≤0.015

Manganese (Mn): ≤0.5

Silicon (Si): ≤0.08

Vanadium (V): ≤0.35

Phosphorus (P): ≤0.02

Sulfur (S): ≤0.02

Product Features

One of the characteristics of Hastelloy C22 alloy is its resistance to stress corrosion cracking. Stress corrosion cracking is a corrosion phenomenon that occurs under stress in specific environments, often leading to material failure. The resistance of Hastelloy C22 alloy to stress corrosion cracking is determined by its chemical composition and austenitic microstructure. Specifically, the chromium and molybdenum in the alloy provide resistance to stress corrosion cracking, while the single-phase austenitic structure makes it strong and durable under stress.

Furthermore, Hastelloy C22 alloy exhibits excellent resistance to localized corrosion. Localized corrosion is a type of corrosion that occurs on the material surface, often due to defects or foreign substances on the surface. The chromium and molybdenum in Hastelloy C22 alloy provide resistance to localized corrosion, thereby enabling its application in chemical industries and other fields.