Oxidizing Resistance Stainless Steel Pipe Reducer Hastelloy C22 UNS N06022

Hastelloy C-22 UNS N06022 NACE MR0175 3'' Reducer STD Pipe Fittings
 
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.
 

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