Hastelloy® C-22 / N06022

Other common names: Alloy C22

Hastelloy C22, also known as alloy C22, is a versatile austenitic nickel-chromium-molybdenum-tungsten alloy with enhanced resistance to pitting, crevice corrosion and stress corrosion cracking. The high chromium content provides good resistance to oxidizing media while the molybdenum and tungsten content give good resistance to reducing media. This nickel steel alloy also has excellent resistance to oxidizing aqueous media including wet chlorine and mixtures containing nitric acid or oxidizing acids with chlorine ions. Other corrosives Hastelloy C-22 has resistance to are oxidizing acid chlorides, wet chlorine, formic and acetic acids, ferric and cupric chlorides, sea water, brine and many mixed or contaminated chemical solutions, both organic and inorganic. This nickel alloy also offers optimum resistance to environments where reducing and oxidizing conditions are encountered in process streams. This is beneficial in multi- purpose plants where such “upset” conditions occur frequently.

This nickel alloy resists the formation of grain-boundary precipitates in the weld heat-affected zone, thus making it suitable for most chemical process applications in the as-welded condition.

Alloy C-22 should not be used in service temperatures above 1250° F due to the formation of detrimental phases which form above this temperature.

Other Designations

Other designations that are equivalent to Hastelloy(r) C22(r) include:

1. ASTM B366
2. ASTM B564
3. ASTM B574
4. ASTM B575
5. ASTM B619
6. ASTM B622
7. DIN 2.4602

   

In what forms is Hastelloy C22 Available at SAGAR STEELS?

• Sheet
• Plate
• Bar
• Pipe & Tube (welded & seamless)
• Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
• Wire

What are the characteristics of Hastelloy C22?

• Resistant to pitting, crevice corrosion and stress corrosion cracking
• Outstanding resistance to both reducing and oxidizing media
• Excellent resistance to oxidizing aqueous media
• Exceptional resistance to a wide variety of chemical process environments including strong oxidizers such as ferric acids, acetic anhydride, and seawater and brine solutions
• Resists the formation of grain-boundary precipitates in the weld heat-affected zone
• Excellent weldability

Chemical Composition, %

In what applications is Hastelloy C22 used?

• Pharmaceutical industries use alloy C-22 fittings and tubing to avoid contamination caused by corrosion related failures
• Cellophane manufacturing
• Chlorination systems
• Pesticide production
• Incineration scrubber systems
• Chemical process industry in equipment like flue gas scrubbers, chlorination systems, sulfur dioxide scrubbers, pulp and paper bleach plants, pickling systems, and nuclear fuel reprocessing
• Waste water processing

ASTM Specifications

Mechanical Properties
Typical Room Temperature Tensile Properties of Annealed Material

Fabrication and Heat Treatment

Machinability

Hastelloy(r) C22(r) can be machined using high-speed steel tooling. Carbide tools are used for milling or turning. Machining operations can be performed using conventional coolants.

Forming

Hastelloy(r) C22(r) can be easily hot or cold formed followed by heat treatment.

Hot Working

Hastelloy(r) C22(r) has good hot working capacity.

Cold Working

Hastelloy(r) C22(r) has cold working capacity.

Welding

Except submerged arc welding method, Hastelloy(r) C22(r) can be welded using all other welding methods.

Heat Treatment

Hastelloy(r) C22(r) is heat treated by annealing at 1122°C (2050°F) followed by quenching.

Forging

Hastelloy(r) C22(r) is hot forged at 1149°C (2100°F) followed by heat treatment.

Aging

Hastelloy(r) C22(r) is aged at 510 to 1038°C (950 to 1900°F) to increase its tensile strength and hardness. However, V-notch impact strength can be degraded if aging is done above 760°C (1400°F).

Hardening

Hastelloy(r) C22(r) cannot be hardened by heat treatment or cold working.

---