Inconel 625 is a corrosion and oxidation resistant nickel alloy that is used  both for its high strength and outstanding aqueous corrosion resistance. Its  outstanding strength and toughness is due to the addition of niobium which acts  with the molybdenum to stiffen the alloy’s matrix. Alloy 625 has excellent  fatigue strength and stress-corrosion cracking resistance to chloride ions. This  nickel alloy has excellent weldability and is frequently used to weld AL-6XN.  This alloy resists a wide range of severely corrosive environments and is  especially resistant to pitting and crevice corrosion. Some typical applications  Inconel 625 is used in are chemical processing, aerospace and marine  engineering, pollution-control equipment, and nuclear reactors.

What are the characteristics of Inconel 625?

· High creep-rupture strength

· Oxidation resistant to 1800° F

· Seawater pitting and crevice corrosion resistant

· Immune to chloride ion stress corrosion cracking

· Non-magnetic

Chemical Composition, %

In what applications is Inconel 625 used?

· Aircraft ducting systems

· Aerospace

· Jet engine exhaust systems

· Engine thrust-reverser systems

· Specialized seawater equipment

· Chemical process equipment

Fabrication with Inconel 625

Alloy 625 has excellent forming and welding characteristics. It may be forged  or hot worked providing temperature is maintained in the range of about  1800-2150° F. Ideally, to control grain size, finish hot working operations  should be performed at the lower end of the temperature range. Because of its  good ductility, alloy 625 is also readily formed by cold working. However, the  alloy does work-harden rapidly so intermediate annealing treatments may be  needed for complex component forming operations. In order to restore the best  balance of properties, all hot or cold worked parts should be annealed and  rapidly cooled. This nickel alloy can be welded by both manual and automatic  welding methods, including gas tungsten arc, gas metal arc, electron beam and  resistance welding. It exhibits good restraint welding characteristics.

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ASTM Specifications

Representative Tensile Properties, bar, 1800° F anneal

Mechanical Properties

Representative Tensile Properties, bar, 1800° F anneal