HASTELLOY alloy C-22 (UNS N06022) is a versatile nickel-chromium-molybdenum-tungsten alloy renowned for its exceptional resistance to a wide range of aggressive chemicals. This article provides a detailed and rich introduction to HASTELLOY C-22, covering its chemical composition, mechanical properties, performance characteristics at different temperatures, industry applications, available shapes and sizes, production standards, welding and processing capabilities, as well as advantages, disadvantages, and comparisons with similar products.
Chemical Composition
Element
Composition (%)
Nickel (Ni)
56.0 min
Chromium (Cr)
20.0 – 22.5
Molybdenum (Mo)
12.5 – 14.5
Iron (Fe)
2.0 – 6.0
Tungsten (W)
2.5 – 3.5
Cobalt (Co)
2.5 max
Manganese (Mn)
0.50 max
Vanadium (V)
0.35 max
Silicon (Si)
0.08 max
Carbon (C)
0.010 max
Phosphorus (P)
0.020 max
Sulfur (S)
0.020 max
Mechanical Properties
Property
Value
Tensile Strength, ksi (MPa)
115 (790) min
Yield Strength (0.2% offset), ksi (MPa)
55 (380) min
Elongation (% in 2 inches)
45 min
Hardness, Rockwell C (HRC)
89 max
Performance at Different Temperatures
HASTELLOY C-22 exhibits excellent performance across varying temperature ranges:
Room Temperature: Superior resistance to oxidizing and reducing acids, including sulfuric acid, hydrochloric acid, and acetic acid.
Elevated Temperatures (up to 1250°F / 677°C): Maintains high strength and corrosion resistance in aggressive chemical environments.
Low Temperatures: Retains ductility and toughness down to cryogenic temperatures, suitable for applications requiring reliability in extreme conditions.
Industry Applications
HASTELLOY alloy C-22 is widely used in several industries due to its exceptional corrosion resistance:
Industry Sector
Applications
Chemical Processing
Reactors, vessels, and piping systems handling corrosive chemicals such as acids and chlorides.
Petrochemical
Equipment for sulfuric acid regeneration, flue gas desulfurization systems, and chemical processing units.
Pharmaceutical
Pharmaceutical processing equipment requiring resistance to aggressive chemicals.
Pulp and Paper
Digesters, bleach plants, and other components exposed to corrosive environments in paper production.
Shapes, Sizes, and Production Standards
Product Form
Shapes Available
Sizes Available
Production Standards
Sheets/Plates
Plates, Sheets
Thickness: 0.025″ – 1.000″ (0.64mm – 25.4mm)
ASTM B575
Bars
Round bars, hexagonal bars
Diameter: 0.25″ – 6.0″ (6.35mm – 152.4mm)
ASTM B574
Tubes/Pipes
Seamless tubes, welded pipes
OD: 0.5″ – 6.0″ (12.7mm – 152.4mm)
ASTM B619, ASTM B622
Standards and Corresponding Grades
Country/Region
Standard/Grade
USA
UNS N06022
Europe
2.4602
Germany
NiCr21Mo14W
France
NC22DNb
Welding, Processing, Polishing, Heat Treatment
Process
Details
Welding
Excellent weldability using TIG, MIG methods, ensuring strong and reliable joints in corrosive environments.
Processing
Machinable using conventional methods, offering flexibility in fabrication processes.
Polishing
Capable of achieving smooth finishes for enhanced corrosion resistance and aesthetic appeal.
Heat Treatment
Solution annealing at 2050°F (1121°C) followed by rapid quenching optimizes material properties and performance.
Cold Processing, Advantages, and Disadvantages
Aspect
Details
Cold Processing
Retains ductility and formability at room temperature, facilitating shaping and fabrication.
Advantages
Exceptional resistance to a wide range of corrosive chemicals, high mechanical strength, and reliability in harsh environments.
Disadvantages
Higher initial cost compared to conventional stainless steels, potential limitations in availability of specific shapes and sizes.
Similar Products
Product Name
Comparison
HASTELLOY C-276 (UNS N10276)
Higher nickel content, broader resistance to oxidizing and reducing environments, suitable for more severe corrosive conditions.
HASTELLOY C-4 (UNS N06455)
Enhanced thermal stability, superior resistance to hot contaminated mineral acids, excellent performance in high-temperature applications.
Comparison of Similar Products
Property/Feature
Hastelloy C-22
Hastelloy C-276
Hastelloy C-4
Nickel Content (%)
56.0
57.0
65.0
Molybdenum Content (%)
12.5 – 14.5
16.0
16.0
Chromium Content (%)
20.0 – 22.5
16.0
16.0
Tensile Strength (ksi)
115 min
100 min
100 min
Yield Strength (ksi)
55 min
40 min
40 min
Corrosion Resistance
Excellent in oxidizing and reducing acids, including sulfuric, hydrochloric, and acetic acid.
Wide range of corrosive environments, including strong oxidizers and reducing agents.
Superior resistance to hot contaminated mineral acids and high-temperature applications.
This article provides an in-depth introduction to HASTELLOY alloy C-22 (UNS N06022), encompassing its chemical composition, mechanical properties, performance in various environments, industry applications, available forms and sizes, production standards, welding and processing capabilities, as well as advantages, disadvantages, and comparisons with similar alloys. The structured format using tables ensures clarity and accessibility of technical information, catering to engineers, manufacturers, and professionals seeking corrosion-resistant materials for demanding applications.
