Alloy C22 Hastelloy C22 Nickel Alloy Welded Pipe DIN 2.4602 ASTM B474

Alloy C22 Hastelloy C22 Nickel Alloy Welded Pipe DIN 2.4602 ASTM B474

ASTM B474
This specification covers electric fusion welded pipe suitable for high-temperature or corrosive service. The pipes are designated into five classes namely Class 1, Class 2, Class 3, Class 4 and Class 5, according to how they are to be welded. The joints shall be full penetration double-welded or single-welded butt joints employing fusion welding processes. The furnished pipe shall undergo heat treatment and a chemical analysis shall be employed for both plate and weld. Each pipe shall be subjected to transverse tension test, transverse guided weld bend test and hydrostatic pressure test.

Hastelloy® C-22

· UNS Number 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.

In what forms is Hastelloy C22 Available at Mega Mex?

· 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

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.

ASTM Specifications

Mechanical Properties

Typical Room Temperature Tensile Properties of Annealed Material