Product Overview
Jiangsu Cunrui Metal Products Co., Ltd. supplies Inconel 686 seamless pipe (UNS N06686, W.Nr. 2.4606) in a balanced Ni-Cr-Mo-W chemistry with the highest combined alloy content of any commercial Ni-Cr-Mo alloy. Because the pipe is seamless, there is no longitudinal weld seam - the entire wall carries the alloy's corrosion resistance, not just the base metal. Every length is cold-worked, solution annealed, hydrostatically tested, and shipped with a mill test certificate traceable back to its heat number.
Chemical Composition & Mechanical Properties
Limiting composition (wt %), per Special Metals technical data / ASTM B622:
| Element | Content (%) |
|---|---|
| Nickel (Ni) | Balance |
| Chromium (Cr) | 19.0 – 23.0 |
| Molybdenum (Mo) | 15.0 – 17.0 |
| Tungsten (W) | 3.0 – 4.4 |
| Iron (Fe) | 2.0 max |
| Titanium (Ti) | 0.02 – 0.25 |
| Carbon (C) | 0.01 max |
| Silicon (Si) | 0.08 max |
| Manganese (Mn) | 0.75 max |
| Phosphorus (P) | 0.04 max |
| Sulfur (S) | 0.02 max |
Mechanical Properties (Room Temperature)
| Property | Typical (solution annealed) | Minimum (per ASTM B622) |
|---|---|---|
| Tensile Strength | 740 MPa (107 ksi) | 690 MPa (100 ksi) |
| Yield Strength (0.2% offset) | 396 MPa (57 ksi) | 310 MPa (45 ksi) |
| Elongation | 60% | 45% |
Why Buyers Choose Inconel 686 Seamless Pipe
Best-in-class localized corrosion resistance - the Cr+Mo+W combination scores higher than Alloy 22, C-276 and 625 in pitting and crevice attack (ASTM G48 data available).
Handles both worlds - resists reducing acids (high Ni + Mo) and oxidizing media (high Cr), including mixed acids with chloride levels above 100,000 ppm at pH ≤ 1.
No weld seam, no weak line - seamless construction eliminates the most common failure point in aggressive service.
Weldable and repairable - can be welded with matching 686CPT consumables for overmatched, fully resistant joints.
Code-ready - ASME P-No. 43 material, NACE MR0175, VdTÜV approved up to 400 °C.
Full traceability - heat numbers, MTCs and third-party inspection (SGS / BV / TÜV) accepted.
Where Inconel 686 seamless pipe Is Used
Chemical & Petrochemical Processing
- Heat exchangers, reactors & columns handling hot sulfuric acid, hydrochloric acid and mixed acid solutions
- Pickling and acid regeneration plants - acid recovery loops, pickle liquor lines and waste acid reclamation
- Pharmaceutical & fine chemical plants requiring high-purity, aggressive-media duty with long service life
Marine & Offshore Oil & Gas
- Sour service piping approved under NACE MR0175 for H₂S-containing production environments
- Offshore platform and subsea lines exposed to seawater and produced fluids with high chloride content
- Marine heat exchangers and cooling water systems where pitting and crevice attack are the failure drivers
Waste Treatment & Power Generation
- Industrial waste acid and leachate treatment lines with fluctuating oxidizing/reducing conditions
- Wastewater and brine concentration systems at elevated temperature
- Power plant auxiliary systems handling aggressive cooling or conditioning chemicals
Stock Program & Available Specifications
Need material fast? The following range is regularly kept in our Inconel 686 seamless pipe stock program, ready for cutting, beveling or direct shipment:
| Parameter | Stock range |
|---|---|
| Outside Diameter | 6.35 – 325 mm (¼" – 12") |
| Wall Thickness | 1.0 – 25.0 mm (0.049" – 1") |
| Length | 3 – 12 m, fixed or random |
| Standards | ASTM B622 (seamless), ASTM B829, ASTM B163; ASME SB622 |
| Surface | Annealed & pickled, or bright annealed |
| Ends | Plain or beveled, cut-to-length |
| Packing | Plastic caps + steel straps + wooden cases, waterproof |
| Documentation | MTC per EN 10204 3.1/3.2, heat traceability |
Other diameters, tolerances (e.g. heavy-wall, tight-OD) and mill-direct quantities can be arranged on request.
About Jiangsu Cunrui Metal Products Co., Ltd.
Jiangsu Cunrui Metal Products Co., Ltd. is a specialized manufacturer and exporter of nickel alloys and special stainless steels, based in Jiangsu, China - one of the country's core metal-processing regions. Our business covers seamless and welded pipes, tubes, plates, sheets, bars, pipe fittings, flanges and forgings in Inconel, Incoloy, Monel, Hastelloy and duplex/super-duplex grades, supported by in-house processing such as cutting, beveling, threading and custom-length supply.We operate a modern production facility equipped with hot-piercing and cold-drawing lines /rolling mills and annealing furnaces,solution annealing and pickling capabilities, and a dedicated inspection team that performs dimensional, PMI and NDT checks before anything ships.
FAQs
Q: What standards do you supply to?
A: Inconel 686 seamless pipe is supplied to ASTM B622 / ASME SB622, plus ASTM B829 and ASTM B163 where applicable. Other specifications can be reviewed case by case.
Q: How does Inconel 686 compare with C-276 or Alloy 22?
A: All three are high-performance Ni-Cr-Mo alloys, but 686 carries a higher combined Cr+Mo+W content, giving it measurably better resistance to pitting, crevice corrosion and stress-corrosion cracking - especially in mixed oxidizing/reducing acids with high chlorides.
Q: Can you supply cut-to-length or beveled ends?
A: Yes. We cut to your specified length and can supply plain, bevelled or threaded ends before shipment.
Q: Do you provide mill test certificates and third-party inspection?
A: Yes. MTCs (EN 10204 3.1, 3.2 on request) with full heat traceability are standard. Third-party inspection by SGS, BV, TÜV or your nominated inspector is welcome.
Q: What is your delivery lead time?
A: Stock items typically ship within 7 days; mill orders take 5 weeks depending on size and quantity
