Incoloy 825 occupies a practical niche: more corruption resistance than any stainless steel but at a far lower cost than Inconel 625, hence its frequent use in the sour wellhead and flowline domination. The welds are solid because of titanium stabilization and copper shields against sulfuric acid while molybdenum protects against chlorides. The composition of Incoloy 825 pipes and tubes is almost 42% nickel in an iron matrix, processed through the annealing method of ASTM B423 or 163.They serve sour oil and gas lines, acid handling and chemical process systems at plants across Oman. Other alloys are on the nickel and exotic alloy pipes and tubes hub.
Where Incoloy 825 Is Used
- Sour and CO2-bearing wellhead, manifold and flowline piping
- Chemical injection and hydraulic control lines
- Sulphuric and phosphoric acid handling
- Pickling equipment and acid regeneration plant
- CRA layer in clad and lined pipelines
Where conditions exceed 825, Inconel 625 is the usual step up; for reducing acids, Hastelloy C276 goes further.
Where 825 Sits Between Stainless and Inconel 625
Property | 316L | Incoloy 825 | Inconel 625 |
|---|---|---|---|
Nickel | 10 to 14% | 38 to 46% | 58% minimum |
Molybdenum | 2 to 3% | 2.5 to 3.5% | 8 to 10% |
Copper | Not specified | 1.5 to 3.0% | Not specified |
Chloride stress corrosion cracking | Susceptible | Resistant, from the high nickel | Resistant |
Sulphuric acid service | Limited | Good, helped by copper | Good |
Relative cost | Baseline | Several times 316L | Higher again |
Titanium is the other working addition. It ties up carbon in the same way it does in stainless 321, so welds resist intergranular attack without a post-weld solution anneal. For sour service, 825 is accepted under NACE MR0175 / ISO 15156-3 within alloy-specific limits, and it is one of the two alloys most often specified for CRA cladding on sour flowlines, the other being 625.
Sour Service, Acids and Limits
Incoloy 825 is accepted for sour service under NACE MR0175 / ISO 15156-3 within alloy-specific limits on H2S, chloride, temperature and, in some cases, cold work. It performs well in sulphuric and phosphoric acid and resists chloride stress corrosion cracking, but in strongly oxidising acids and in the most aggressive reducing conditions the higher-molybdenum alloys do better. State your service conditions in the RFQ; requirements are confirmed at quotation.
What Affects the Price of Incoloy 825
- Alloy surcharges, which move with nickel, molybdenum and chromium markets
- Seamless or welded
- Size, schedule or wall, and length
- Surface finish and any polishing
- 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, certification, inspection, destination port and required date.
Incoloy 825 Certificates and Inspection
Incoloy 825 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 fittings and B564 flanges in the same alloy.
Incoloy 825 is used across upstream oil and gas and sour service, fertilizer and refinery and petrochemical plants.
Incoloy 825 FAQ
What is Incoloy 825?
A nickel-iron-chromium alloy with molybdenum, copper and titanium, UNS N08825, used for sour service, acids and chloride-bearing conditions.
Why does 825 contain copper?
Copper improves resistance in sulphuric acid and other reducing acids.
Is 825 accepted for sour service?
Yes, under ISO 15156-3 within alloy-specific limits, which may include restrictions on cold work.
How does 825 compare with Inconel 625?
625 has far more molybdenum and handles more severe conditions, at a higher price. 825 covers many sour and acid duties at lower cost.
Why is titanium added?
It ties up carbon so welds resist intergranular attack without a post-weld solution anneal.
What should I send for a quotation?
Send the UNS number, standard, form, size, wall, length, quantity, service conditions, testing, certification and destination port.
Request a Quote for Incoloy 825 Pipes and Tubes
Send the UNS number, size, wall and quantity, with the fluid, H2S and temperature conditions. Every enquiry is checked before the offer is prepared, so 825 is confirmed as sufficient rather than assumed.