Introduction

Hastelloy C22 Alloy (UNS N06022) is a nickel-chromium-molybdenum-tungsten alloy with controlled iron additions, designed for the most demanding corrosive environments. This nickel-chromium-molybdenum alloy contains approximately 56% nickel, 22% chromium, 13% molybdenum, and 3% tungsten, with a low carbon design (<0.015%). The alloy offers exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking, while providing outstanding protection in both oxidizing and non-oxidizing conditions. This corrosion resistant Hastelloy C22 is significantly more resistant to wet chlorine environments than Alloy C276 and exhibits better thermal stability than C-4. Available in Hastelloy C22 plate, sheet, strip, pipe, tube, bar, round bar, wire, fittings, flanges, and forgings, in hot rolled, cold rolled, cold drawn, annealed, and solution annealed conditions.

Chemical components (%) 

Physical properties

Hastelloy C22 Available Products and Standard

1. GB/T 15007 (Nickel and Nickel Alloy Plate, Strip, and Foil)

Domestic Grade: NS3308 (GB/T 15007) / Hastelloy C22 equivalent

Type: Sheet / Plate / Strip / Wire / Tube / Bar

Size Range:

• Hastelloy C-22 Alloy Wire: 0.1 – 15.0 mm dia

• Hastelloy C-22 Alloy Strip: 0.05 – 5.0 mm thick × 5 – 500 mm wide

• Hastelloy C-22 Alloy Round Bar: 8 – 355 mm dia

• Hastelloy C-22 Alloy Sheet / Plate: 0.5 – 180 mm thick

• Hastelloy C-22 Alloy Seamless Tube / Pipe: Custom sizes available

Surface: Annealed, Bright, Pickled, Ground

Testing: Chemical analysis, mechanical test (tensile strength, yield strength, elongation), hardness test, intergranular corrosion test, pitting corrosion test, dimensional inspection

2. ASTM B574 (Standard Specification for  Inconel 622 Alloy Rod and Bar)

Type: Round Bar / Rod / Wire

Size Range:

• Hastelloy C-22 Alloy Round Bar: 8 – 355 mm dia (hot rolled or cold drawn)

• Hastelloy C-22 Alloy Wire: 0.1 – 15.0 mm dia (coils or straight)

Surface: Annealed, Pickled, Ground, Turned, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, ultrasonic test, dimensional inspection

3. ASTM B575 (Standard Specification for  Inconel 622 Alloy Plate, Sheet, and Strip)

Type: Sheet / Plate / Strip

Size Range:

• Hastelloy C-22 Alloy Sheet / Plate: 0.5 – 180 mm thick (hot rolled or cold rolled)

• Hastelloy C-22 Alloy Strip: 0.05 – 5.0 mm thick × up to 500 mm wide (coils)

Surface: Annealed, Pickled, Bright, Polished

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hardness test, intergranular corrosion test, pitting corrosion test, dimensional inspection

4. ASTM B622 (Standard Specification for Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube)

Type: Seamless Pipe / Seamless Tube

Size Range:

• Hastelloy C-22 Alloy Seamless Pipe: 6 – 610 mm OD × 1 – 50 mm wall thickness

• Hastelloy C-22 Alloy Seamless Tube: Custom sizes

Surface: Annealed, Pickled, Bright

Testing: Chemical analysis, mechanical test (tensile, yield, elongation), hydrostatic test, eddy current test, dimensional inspection

Applications

1. Chemical Processing & Petrochemical Industry

• In reactors, heat exchangers, and columns for the chemical process industry (CPI), Hastelloy C22 plate and UNS N06022 pipe deliver superior resistance to a wide variety of chemical process environments, including strong oxidizers such as ferric and cupric chlorides, chlorine, and hot contaminated organic and inorganic solutions.

• For formic acid, acetic acid, and acetic anhydride service, Alloy C22 seamless pipe provides exceptional resistance to both uniform and localized corrosion.

• Hastelloy C22 alloy resists the formation of grain-boundary precipitates in the weld heat-affected zone, making it suitable for most chemical process applications in the as-welded condition—eliminating the need for post-weld heat treatment.

• For pesticide production, chlorination systems, and cellophane manufacturing, Hastelloy C22 tube provides the corrosion resistance required for aggressive chemical environments.

2. Flue Gas Desulfurization & Pollution Control

• In flue gas desulfurization (FGD) scrubbers, stack-gas reheaters, and absorber towers, Hastelloy C22 sheet and plate withstand the highly corrosive, low-pH, chloride-rich environments characteristic of FGD systems.

• For flue gas scrubbers and environmental technology equipment, Alloy C22 pipe resists oxidizing aqueous media including wet chlorine and mixtures containing nitric acid or oxidizing acids with chloride ions.

• Hastelloy C22 for pollution control equipment is specified for waste incineration scrubbers, industrial waste treatment systems, and flue gas purification equipment.

3. Oil & Gas / Offshore Engineering

• For offshore platforms, subsea equipment, and topside process piping, Hastelloy C22 seamless pipe offers premier resistance to chloride-induced pitting and crevice corrosion in seawater and brine environments.

• Hastelloy C22 for oil and gas handles H₂S/CO₂ environments, sour gas service, and produced water systems—with NACE MR0175 compliance for sour service applications.

• UNS N06022 tube is widely used in subsea control lines, risers, and platform utility systems where exposure to seawater and corrosive well fluids is unavoidable.

4. Pharmaceutical Equipment & Power Generation

• For pharmaceutical reactors, API synthesis vessels, and clean-in-place systems, Hastelloy C22 bar and tube maintain product purity with non-contaminating corrosion resistance through high-temperature sterilization cycles.

• In power generation applications—including industrial furnaces, gas turbine components, and heat recovery systems—Hastelloy C22 alloy retains mechanical strength at elevated temperatures with excellent oxidation resistance.

• Hastelloy C22 fittings and flanges are specified for critical connections in pharmaceutical and power generation equipment.

5. Nuclear Fuel Reprocessing & Industrial Equipment

• For nuclear fuel reprocessing equipment and radioactive waste handling, Hastelloy C22 plate provides the corrosion resistance and radiation stability required for demanding nuclear applications.

• For expansion bellows, seals, springs, and fasteners in aggressive environments, Hastelloy C22 wire and strip deliver reliable performance.

FAQ – Hastelloy C22 Alloy

Q: What is the difference between Hastelloy C22 and Hastelloy C276?

A: Hastelloy C22 (UNS N06022) has higher chromium content (22% vs 15.5%), providing superior resistance to oxidizing environments. Hastelloy C276 has higher molybdenum content, offering better resistance to reducing acids. For environments that fluctuate between oxidizing and reducing conditions, C22 is the safer choice because its higher chromium provides a broader corrosion resistance envelope. C22 also offers significantly better resistance to wet chlorine environments and crevice corrosion in chloride-containing applications.

Q: Can Hastelloy C22 be welded without post-weld heat treatment?

A: Yes. Hastelloy C22 seamless pipe can be welded using TIG, MIG, SMAW, and SAW techniques. The alloy resists the formation of grain-boundary precipitates in the weld heat-affected zone, making it suitable for most chemical process applications in the as-welded condition. Unlike some other nickel alloys, C22 does not sensitize during heating or welding. No post-weld heat treatment is required for most applications.

Q: What is the maximum operating temperature for Hastelloy C22?

A: Hastelloy C22 alloy offers excellent oxidation resistance at elevated temperatures and maintains mechanical properties across a wide temperature range. It is suitable for continuous service in oxidizing atmospheres up to approximately 1900°F (1038°C). The alloy also performs well in cryogenic applications, retaining ductility and toughness at low temperatures.

Q: What industries commonly use Hastelloy C22?

A: Chemical processing (reactors, heat exchangers, columns, transfer pipes), petrochemical industry, oil and gas (offshore platforms, sour gas service), flue gas desulfurization and pollution control, pharmaceutical equipment, nuclear fuel reprocessing, power generation, marine engineering, and industrial equipment manufacturing. This corrosion resistant nickel alloy is the material of choice for applications requiring broad-spectrum corrosion protection across both oxidizing and reducing environments.

MONO Group specializes in the supply of Hastelloy C‑22 and a comprehensive portfolio of nickel‑chromium‑molybdenum alloys for chemical processing, pharmaceutical, and pollution control applications. As a China‑based manufacturer and wholesale distributor, we offer plates, sheets, round bars, seamless tubes, welded pipes, fittings, flanges, and custom‑machined parts – all produced in accordance with ASTM, ASME, DIN, ISO, and GB specifications. We also provide cut‑to‑size, precision machining, and surface finishing services to meet your project requirements. For detailed technical datasheets, stock availability, or a competitive quotation, please contact us at info@monokj.com – our team is ready to assist with fast, expert responses.