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.

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

Fabrication of Hastelloy C-22

Although ductile enough to be formed by cold working, intermediate annealing  may be necessary due to work hardening. Forging should be performed between  1750-2050° F followed by rapid cooling. Annealing can be performed at a  temperature range between 2020-2150° F followed by a rapid quench. Cooling at an  accelerated rate avoids the formation of detrimental phases which form between  1400-1800° F. Welding can be done by gas tungsten-arc, gas metal-arc and  shielded metal-arc processes.

For more information on fabrication and machining, click here.

ASTM Specifications

Mechanical Properties

Typical Room Temperature Tensile Properties of Annealed Material