B2

Wst. 2.4617
UNS N010665

Stock program: Available on request

Specification: ASTM B 622/ASME SB 622/ASTM B 626/ASME SB 626
Seamless and welded conditions

Maximum expose temperature:    
till 400°C/750°F and from 870°C/1600°F till 1100°C/2000°F
(because of reduction in the ductility for temperatures in between)

Alloy B2 is a nickel-molybdenum solution strengthened alloy, with outstanding resistance to reducing environments like hydrogen chloride gas, acetic , pure sulfuric and phosphoric acids, due to the primary alloying element molybdenum. The alloy should not be used in oxidizing media or where oxidizing contaminants are available in reducing media. It is not recommended to use alloy B2 in a system containing hydrochloric acid where iron or copper is present, this may cause premature corrosion failure.

Characteristics   

• Excellent resistance to a wide range of organic acids
• Good resistance to chloride-induced stress corrosion cracking and pitting corrosion
• Resistance to hydrochloric acid at any concentration and temperature
• B2 loses it ductility when it’s exposed to temperatures between 538-870°C/980-1600°F, processing and use in this temperature range must be avoided
• Resist the formation of grain boundary carbide precipitates in the weld heat-affected zone

Market applications:

•    Chemical processing
•    Mechanical components in reducing environments
•    Vacuum furnaces
•    Heat exchanges

Technical details