Nickel Alloy 625 | UNS N06625 | 2.4856 | Inconel 625

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies Nickel Alloy 625, also known as Inconel 625, identified as UNS N06625 and Werkstoff 2.4856 (EN designation NiCr22Mo9Nb), in plate, sheet, strip, round bar, wire, pipe, tube, and forging forms.

Our Alloy 625 plate and sheet products can be supplied according to ASTM B443 / ASME SB-443 and aerospace standard AMS 5599. Other product forms are available to ASTM B446 (bar and wire), ASTM B444 (seamless pipe and tube), and AMS 5666 (forgings).

Nickel Alloy 625 is a nickel-chromium-molybdenum alloy with an addition of niobium, which acts with the molybdenum to stiffen the alloy's matrix, providing high strength without the need for a strengthening heat treatment. The alloy resists a wide range of severely corrosive environments and is especially resistant to pitting and crevice corrosion. With a density of 8.44 g/cm³ and a melting range of 1,290 – 1,350°C, it maintains high strength and toughness across a broad temperature range from cryogenic conditions up to 982°C (1,800°F), with short-term service possible to 1,000°C.

Actual properties depend on product form, dimensions, heat-treatment cycle, and the specified standard.

Alloy 625 is normally supplied in the annealed condition. The alloy is not age-hardenable – high strength is achieved through solid solution strengthening from molybdenum and niobium additions, without the need for precipitation hardening. Annealed properties: tensile strength ≥ 760 MPa, yield strength ≥ 380 MPa, elongation ≥ 35%.

• Grade 1: Describes the alloy in the annealed condition, suitable for most applications.
• Grade 2: Describes the alloy in the solution annealed condition, recommended for application temperatures above 600°C.

In the temperature range between approximately 650°C and 850°C, this alloy has a tendency to become brittle. This must be taken into account in the design of equipment.

Alloy 625 offers outstanding resistance to a wide range of severely corrosive environments, making it one of the most versatile nickel alloys available.

• Excellent resistance to pitting and crevice corrosion due to high molybdenum and chromium content
• Superior resistance to chloride stress-corrosion cracking
• Resistance to intergranular attack in the as-welded condition due to niobium stabilization
• Good resistance to mineral acids: nitric, phosphoric, sulfuric, and hydrochloric acids
• Resistance to alkalis and organic acids
• Excellent oxidation resistance up to 982°C (1,800°F), with short-term service to 1,000°C
• High resistance to seawater, particularly in high-velocity conditions – a favorable choice for marine applications
• Good weldability and resistance to weld decay
• Non-magnetic, austenitic structure

• Brittleness risk in the 650°C – 850°C range must be considered in design.
• For applications above 600°C, the solution-annealed finish should be selected.
• NACE MR0175 / ISO 15156 compliant for sour-service applications when properly processed.
• Final selection must consider the specific medium, concentration, temperature, and exposure conditions.

• Chemical Processing: Reactors, heat exchangers, piping systems, valves, pumps for aggressive acid environments
• Offshore and Marine: Seawater piping, riser linings, offshore platforms, marine engineering components
• Aerospace: Turbine components, engine parts
• Environmental Technology: Flue gas desulfurization scrubbers, waste incineration systems
• Nuclear: Radioactive waste treatment, nuclear reactor components
• Oil and Gas: Production piping, cladding for corrosion protection, risers

Available quality-control services include:

• Heat-number traceability
• Chemical composition verification
• Tensile, yield and elongation testing
• Hardness inspection
• Dimensional and surface inspection
• Positive Material Identification (PMI)
• Ultrasonic testing
• Dye penetrant inspection
• Heat-treatment records
• EN 10204 3.1 material certificate

For an accurate quotation, please provide:

Alloy Grade · Standard · Product Form · Dimensions · Quantity · Heat Treatment · Inspection Requirement · Application · Working Temperature · Destination Port

For corrosive environments, also provide:

Chemical Medium · Concentration · Temperature · Oxidizing or Reducing Conditions

• Request Alloy 625 Plate Quote
• Upload Drawing or MTO
• Check Available Stock
• Ask for Alloy Selection Support

1. What is ASTM B443 Alloy 625?

ASTM B443 Alloy 625 (UNS N06625), also known as Inconel 625, is a nickel-chromium-molybdenum-niobium alloy with excellent corrosion resistance and high strength from cryogenic to 982°C without heat treatment.

2. What are the UNS and EN numbers for Alloy 625?

The UNS designation is N06625; the European Werkstoff number is 2.4856; the EN material symbol is NiCr22Mo9Nb.

3. Which standard applies to Alloy 625 plate?

ASTM B443 / ASME SB-443 applies to plate, sheet and strip. AMS 5599 and AMS 5869 are also applicable aerospace standards.

4. Which standards apply to other product forms?

ASTM B446 / AMS 5666 for bar and wire; ASTM B444 / ASME SB-444 for seamless pipe and tube; ASTM B564 for forgings.

5. Does Alloy 625 require heat treatment?

No. Alloy 625 is not age-hardenable. High strength is achieved through solid solution strengthening, requiring no strengthening heat treatment.

6. What environments does Alloy 625 resist?

It resists pitting, crevice corrosion, chloride stress-corrosion cracking, mineral acids (nitric, phosphoric, sulfuric, hydrochloric), alkalis, organic acids, seawater, and oxidation up to 982°C.

7. Is Alloy 625 suitable for seawater?

Yes. Alloy 625 is a favorable choice for seawater applications, with excellent resistance to pitting and crevice corrosion in marine environments.

8. What is the maximum service temperature for Alloy 625?

Alloy 625 maintains integrity up to 982°C (1,800°F) for oxidation resistance, with short-term service possible to 1,000°C.

9. Can Alloy 625 be welded?

Yes. Alloy 625 exhibits excellent weldability with good resistance to intergranular attack in the as-welded condition.

10. What information is required for a quotation?

Please provide the standard, product form, dimensions, quantity, heat-treatment condition, inspection requirements, application, working temperature and destination port. For corrosive environments, also specify the chemical medium and concentration.