Inconel alloy 625/UNS N06625/W.Nr. 2.4856 ASTM B446 wire bar sheet

Overview

INCONEL nickel-chromium alloy 625 (UNS N06625/W.Nr. 2.4856) is used for its high strength, excellent fabricability (including joining), and outstanding corrosion resistance. Service temperatures range from cryogenic to 1800°F (982°C).

The strength of INCONEL 625 alloy is due to the strengthening of its nickel-chromium matrix by molybdenum and niobium, so there is no need for precipitation hardening. This combination of elements has superior properties in dealing with a variety of extremely harsh corrosive environments as well as high temperature oxidation and carbonization.

INCONEL alloy 625 is suitable for Marine applications due to the following characteristics: no local corrosion (pitting and crevices), high corrosion fatigue strength, high tensile strength, and resistance to chloride ion stress corrosion cracking.

High tensile, creep and fracture strength; Excellent fatigue and thermal fatigue strength; Antioxidant properties; The excellent weldability and brazing properties of INCONEL alloy 625 have made it of interest in the aerospace field. It is widely used in aircraft duct system, engine exhaust system, thrust reversal system and many other fields.

In the nuclear field, INCONEL alloy 625 may  be used for reactor-core and control-rod components in  nuclear water reactors. The material can be selected  because of its high strength, excellent uniform corrosion resistance, resistance to stress cracking and excellent pitting resistance in 500°-600°F (260-316°C) water. Alloy 625 is also being considered in advanced  reactor concepts because of its high allowable design  strength at elevated temperatures, especially between 1200°-1400°F (649-760°C).

Limiting Chemical Composition, % 

Nickel......................................................................................................................................................................................58.00 min.

Chromium............................................................................................................................................................................20.00-23.00

Iron...........................................................................................................................................................................................5.00 max.

Molybdenum ........................................................................................................................................................................8.00-10.00

Niobium (plus Tantalum).......................................................................................................................................................3.15-4.15

Carbon.....................................................................................................................................................................................0.10 max.

Manganese..............................................................................................................................................................................0.50 max.

Silicon.......................................................................................................................................................................................0.50 max.

Phosphorus...........................................................................................................................................................................0.015 max.

Sulfur......................................................................................................................................................................................0.015 max.

Aluminum.................................................................................................................................................................................0.40 max.

Titanium....................................................................................................................................................................................0.40 max.

Cobalta......................................................................................................................................................................................1.00 max.

Physical Constants

Mechanical properties

For service at 1200°F and below, hotfinished, cold-finished, and annealed conditions (depending on requirements involved) are recommended.

For service above 1200°F, either annealed or solution-treated material will give best service.

The solution-treated condition is recommended for components that require optimum resistance to creep or rupture. Fine-grained (annealed) material may be advantageous at temperatures up to 1500°F with respect to fatigue strength, hardness, and tensile and yield strength.

Tensile-properties

Corrosion Resistance

The high alloy content of INCONEL alloy 625 enables it to withstand a wide variety of severe corrosive environments. In mild environments such as the atmosphere, fresh and sea water, neutral salts, and alkaline media there is almost no attack. In more severe corrosive environments the combination of nickel and chromium provides resistance to oxidizing chemicals, whereas the high nickel and molybdenum contents supply resistance to nonoxidizing environments. The high molybdenum content also makes this alloy very resistant to pitting and crevice corrosion, and niobium acts to stabilize the alloy against sensitization during welding, thereby preventing subsequent intergranular cracking. Also, the high nickel content provides freedom from chloride ion stresscorrosion cracking.

Heat Treatment

Hot- or cold-formed parts are usually annealed at 1700°-1900°F for times commensurate with thickness; higher temperatures may be used to soften material for additional cold work. INCONEL alloy 625 is solution-treated at 2000°-2200°F. These temperatures are metal temperatures based on batch operations and may not apply to continuous annealing, which normally consists of short exposure in the hot zone of a furnace set at higher temperatures. The rate of cooling after heating has no significant effect on INCONEL alloy 625.

According to tests,Heating cold-drawn material at 1100° to 1400°F reduces residual stress. Stress relief is virtually complete when the material is heated to 1600°F.

Available Forms

We provide you with a variety of product forms, including but not limited to

● Bar & Rod

● Pipe & Tube

● Coil & Strip

● Plate & Sheet & Circle

● Wire & Welding

● Fitting (Flange, Elbow, Tee...)

● Customize