ASTM B444 UNS N06625 Nickel Alloy Pipes Seamless Alloy 400 Tubing

Description:

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.

Characteristics:

Excellent mechanical properties at both extremely low and extremely high temperatures.

Outstanding resistance to pitting, crevice corrosion and intercrystalline corrosion.

Almost complete freedom from chloride induced stress corrosion cracking.

High resistance to oxidation at elevated temperatures up to 1050C.

Good resistance to acids, such as nitric, phosphoric, sulfuric and hydrochloric, as well as to alkalis makes possible the construction of thin structural parts of high heat transfer.

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.

Applications:

Components where exposure to sea water and high mechanical stresses are required.

Oil and gas production where hydrogen sulfide and elementary sulfur exist at temperature in excess of 150C.

Components exposed to flue gas or in flue gas desulfurization plants.

Flare stacks on offshore oil platforms.

Hydrocarbon processing from tar-sand and oil-shale recovery projects.

ASTM Specifications:

Mechanical Properties:

Representative Tensile Properties, bar, 1800° F anneal