Inconel 625 comes in two types of annealed forms. These are different from each other and lead to variation in the behavior of the material with respect to high temperature use. The softer product is good for corrosion resistance and forming. Getting the grade designation right is half the order. The Inconel 625 varieties of tubes and pipes are manufactured with 21% chromium and 9% molybdenum material along with the addition of niobium. With such composition, it becomes immune to acidic solutions and can withstand seawater as well as temperatures. It appears in wellhead lines, flare systems and clad pipelines across Oman. Other alloys are on the nickel and exotic alloy pipes and tubes hub.
Where Inconel 625 Is Used
- Sour and CO2-bearing wellhead, manifold and flowline piping
- Subsea and topside hydraulic and chemical injection lines
- Flare and vent systems at high temperature
- Seawater and brine handling on offshore facilities
- CRA layer in clad and lined pipelines, and as weld overlay on carbon steel
For less severe sour service, Incoloy 825 is more economical; for reducing acids, Hastelloy C276 goes further. Clad options are on the CRA clad and lined pipes page.
Grade 1 or Grade 2: The Condition Matters
Condition | How it is supplied | Where it is used |
|---|---|---|
Annealed (often called Grade 1) | Annealed at the lower temperature range | Corrosion service, forming and general piping |
Solution annealed (often called Grade 2) | Solution annealed at a higher temperature, giving lower room-temperature strength but better creep behaviour | High-temperature service, where the design code requires it |
The two conditions share the same chemistry and look identical. Room-temperature strength is higher in the annealed condition, which sometimes leads buyers to assume it is the better material; for hot service the solution annealed condition is what the code allows. State the ASTM grade or condition on the enquiry, not just "Inconel 625".
A second use worth knowing. Inconel 625 is also the usual weld overlay and cladding alloy for carbon steel, so the same designation appears on clad pipe orders where only a few millimetres of the alloy are involved. That is a different product with a different cost base, covered on the CRA clad and lined pipes page.
Sour Service and Corrosion
Inconel 625 is one of the corrosion-resistant alloys accepted for severe sour service under NACE MR0175 / ISO 15156-3, within alloy-specific limits that cover H2S partial pressure, chloride, temperature and, in some cases, cold work and hardness. It also resists seawater, oxidising and reducing conditions across a wide range, which is why it appears both as solid pipe and as a clad layer. State your service conditions, including any cold-work restrictions, in the RFQ; requirements are confirmed at quotation.
What Affects the Price of Inconel 625
- Alloy surcharges, which move with nickel, molybdenum and chromium markets
- Seamless or welded
- Size, schedule or wall, and length
- Surface finish and any polishing
- Nickel, molybdenum and niobium content, which make 625 one of the more expensive corrosion alloys
- Testing, including corrosion testing and PMI
- Quantity and stock availability versus a mill order
- Certification (EN 10204 3.1 or 3.2) and third-party inspection
- Incoterm and destination port
Quotations are available in USD, OMR, AED, SAR, QAR, KWD and BHD, on EXW, FOB, CFR or CIF terms.
What to send for a quotation:
grade, standard, seamless or welded, NPS or OD, schedule or wall, length, quantity, finish, testing, the ASTM grade or condition required, certification, inspection, destination port and required date.
Inconel 625 Certificates and Inspection
Inconel 625 is supplied with EN 10204 3.1 certificates as standard, and EN 10204 3.2 certificates on request. Inspection by the buyer's nominated third-party agency can be arranged; state your requirement in the RFQ. Check the chemistry, the heat treatment condition, tensile results and any corrosion test report. PMI on receipt confirms the grade. See the MTC and EN 10204 certification guide.
Packing and Site Storage
Lead time is confirmed at quotation. Material ships with end caps and, where specified, protective wrapping. Keep it away from carbon steel racks, slings and grinding dust, since embedded iron rusts on the surface and can start pitting. On coastal Gulf sites, rinse salt deposits off before fabrication.
Fittings and Related Alloys
Match with ASTM B366 WPNCMC fittings and B564 flanges in the same alloy.
Inconel 625 is used across upstream oil and gas and sour service, marine and offshore and refinery and petrochemical facilities.
Inconel 625 FAQ
What is Inconel 625?
A nickel-chromium-molybdenum alloy with niobium, UNS N06625, used for severe corrosion and sour service and for high-temperature duty.
What is the difference between the two annealed conditions?
The annealed condition has higher room-temperature strength and suits corrosion service and forming. The solution annealed condition is specified for high-temperature service.
Is Inconel 625 suitable for sour service?
Yes, within the alloy-specific limits of ISO 15156-3, which may include restrictions on cold work and hardness.
Why is 625 used for cladding?
It bonds well to carbon steel and gives excellent corrosion resistance in a thin layer, which makes long pipelines affordable.
What is the EN equivalent?
2.4856 (NiCr22Mo9Nb).
What should I send for a quotation?
Send the UNS number, ASTM standard and condition, form, size, wall, length, quantity, service conditions, testing, certification and destination port.
Request a Quote for Inconel 625 Pipes and Tubes
Send the UNS number, ASTM condition, size and quantity, with the service conditions. Every enquiry is checked before the offer is prepared, so the annealed and solution annealed conditions are never confused on a hot service line.