Sihe Steel
Sihe Steel
Engineered to withstand extreme temperature ranges, deepwater pressures, and corrosive chemical exposures
An authoritative breakdown of mechanical performance, composition advantages, and material integrity benchmarks
Alloy 625 is a nickel-chromium-molybdenum alloy with niobium added to act as a stabilizer. It is renowned for its high strength, excellent fabricability, and outstanding corrosion resistance in environments ranging from cryogenic temperatures to 1800°F (982°C). Unlike precipitation-hardened alloys, its strength is derived from the solid-solution strengthening effect of molybdenum and niobium within its nickel-chromium matrix.
"The synergistic behavior of molybdenum and niobium in the nickel-chromium matrix provides high resistance to pitting, crevice corrosion, and intergranular attack without needing secondary thermal treatment."
Due to these properties, Alloy 625 coiled tubing is ideal for chemical injection lines, control lines, subsea umbilical lines, and downhole operations in sour environments containing H2S, CO2, and high levels of chloride.
| Element | Nickel (Ni) | Chromium (Cr) | Molybdenum (Mo) | Niobium + Tantalum (Nb+Ta) | Iron (Fe) | Carbon (C) | Manganese (Mn) | Silicon (Si) |
|---|---|---|---|---|---|---|---|---|
| Min (%) | 58.0 | 20.0 | 8.0 | 3.15 | - | - | - | - |
| Max (%) | - | 23.0 | 10.0 | 4.15 | 5.0 | 0.10 | 0.50 | 0.50 |
For over ten years, Liaocheng Sihe Stainless Steel Material LTD has been at the forefront of engineering and exporting high-performance stainless steel and nickel alloy coiled tubing. Operating six advanced production lines, we adhere to the most stringent international standards including GB, ASTM, ASME, JIS, and EN.
Our facility introduces world-class bright annealing technology, allowing online heat treatment to achieve maximum ductility and surface cleanliness. Our range of alloys includes 304/304L, 316L, 321, 317L, 309S, 310S, INCOLOY 800, Austenitic 316L, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625.
We guarantee safe, long-length continuous configurations of up to 32,800 feet (10,000 meters) to eliminate orbital weld junctions, reducing leak risks and logistical complexities in offshore setups.
How Alloy 625 coiled tubing serves critical roles in high-stakes structural, chemical, and energetic programs
For subsea injection systems and dynamic deepwater wells, control lines require massive continuous lengths without orbital welds. Our 10,000-meter continuous coils minimize leak paths and provide structural stability under hydrostatic pressures up to 15,000 psi.
Superheated geothermal steam is rich in hydrogen sulfide and chloride ions, driving standard steels to fail via stress corrosion cracking. Alloy 625 resists severe downhole environments, permitting uninterrupted energy extraction.
Alloy 625 is deployed in extreme thermal aerospace environments where fuel and hydraulic systems interface directly with hot exhaust zones. Its high yield strength ensures lightweight, thin-walled tubing design without structural risk.
Our coiled tubes are verified for compliance across various heavy industrial systems worldwide
Providing extensive traceability documentation, third-party approvals, and chemical reports
Our manufacturing and quality assurance programs comply with global design standards for tubular products, ensuring safe installation in extreme and pressurized environments.
Every meter of our coiled tubing is verified through rigorous testing before shipping to international clients:
Testing pressure resistance up to 100 MPa.
Nondestructive testing to detect microscopic wall defects.
Mechanical tests proving cold workability and weld seam strength.
Mechanical verification of yield strength, UTS, and elongation.
State-of-the-art technological capabilities configured for your engineering specifications
We provide custom cold bending, orbital routing, and spiral coil configuration. Perfect for helical steam heat exchangers and compact downhole chambers.
Our drawing process optimizes control over dimensional tolerances and mechanical properties, yielding uniform wall thickness and concentricity.
Equipped with advanced straightening lines and high-precision laser and mechanical cutting options, we deliver ready-to-weld tube ends with zero deformation.
Using a hydrogen-controlled atmosphere, online bright annealing prevents scaling and decarbonization, ensuring a clean, residue-free internal diameter (ID).
High-quality flanged and flared tube ends eliminate structural stress concentrators in high-vibration systems and pressure fittings.
Our coils are shipped on reinforced metal or wooden spools, wrapped in heavy-duty plastic, and protected by wooden crates to prevent transit damage.
Explore our manufacturing range for various configurations of coiled and capillary tubing
Duplex 2205, Super Duplex 2507, and nickel alloy coils engineered for oil recovery and subsea deployment.
High-precision austenitic steel (304/304L, 316/316L) and nickel alloys for chemical transmission lines.
Designed for high-temperature furnace piping, boiler tubes, and hydrocarbon reforming systems.
Perfect for downhole control lines, subsea hydraulics, and instrumentation panels.
Long continuous seamless coils designed for high fatigue resistance and reliability under deepwater sea conditions.
Designed for acidic reactors, processing plants, and marine exhaust systems.
Small-bore tubing ranging from 0.125" OD down to capillary scales for gas chromatography and analysis equipment.
Engineered for high thermal conductivity and corrosion resistance in marine boilers and condensers.
combining high mechanical strength with pitting resistance (PREN > 35) for aggressive fluid transmission.
Custom dimensions in Incoloy 825, Inconel 625, and Monel 400 for aggressive acids.
Cold drawn seamless tubing ensuring no weld seams, uniform structural integrity, and high pressure ratings.
Internally and externally polished surfaces for ultra-pure systems like semiconductors and biopharmaceuticals.
Corrosion-resistant backing plates and sheets, matching our coiled tubes' metallurgy for seamless fabrication.
The evolution of high-alloy coiled tubing in green energy transition, deepwater horizons, and hydrogen systems
As the global energy transition accelerates, hydrogen transportation and storage infrastructure present new metallurgical challenges. Conventional steels are susceptible to hydrogen embrittlement, which can lead to catastrophic cracking. Our metallurgical department is developing and testing Alloy 625 coiled tubing configurations specifically optimized to resist hydrogen embrittlement under high pressures.
These optimized materials feature extremely low inclusion limits and controlled grain structures, ensuring long-term safety for critical hydrogen distribution networks.
While continuous lengths of up to 32,800 feet are standard, some offshore installations require even longer runs. Our advanced joining processes involve automated orbital TIG welding, followed by 100% radiographic examination and localized induction annealing. This ensures that the weld line matches the parent tube's corrosion resistance and mechanical properties, preventing premature failure at transition joints.
Get answers to common technical, commercial, and logistical queries regarding our products
Seamless coiled tubing is cold drawn from a solid billet, offering uniform grain structure and no weld line, which is ideal for high-pressure and fatigue-critical applications. Welded and redrawn tubing is made from strip material, welded longitudinally, and then drawn over a mandrel to smooth the weld. While welded and redrawn options are cost-effective and suitable for many applications, critical subsea and downhole installations typically specify seamless tubing to avoid weld line degradation.
Although Duplex 2205 offers high strength and good chloride resistance, Alloy 625 (UNS N06625) provides superior corrosion resistance in high-temperature, sour service (H2S and CO2) applications. Additionally, Alloy 625 remains ductile at extreme temperatures, whereas duplex steels can suffer from embrittlement at elevated service ranges.
Depending on the outer diameter and wall thickness, we can supply continuous lengths of up to 32,800 feet (10,000 meters) on a single reel. This reduces or eliminates the need for orbital butt welds, which are common failure points in offshore chemical injection and umbilical lines.
We provide comprehensive documentation packages, including Mill Test Certificates (MTC) to EN 10204 3.1, Chemical Analysis, Mechanical Test Reports, Nondestructive Testing (NDT) results (Eddy Current, Hydrostatic), Heat Treatment logs, and Certificate of Origin (CO).
For custom production and large orders, lead times range from 20 to 30 days after receipt of downpayment and drawing approvals. Samples and stock items can be processed for dispatch within 7 days.
Coiled tubing is wound on reinforced steel or wooden reels, secured against shifting, and wrapped in protective layers to prevent water and salt exposure. Heavy-duty wooden crates or frames are used to ensure the reels remain stable during sea freight transport.
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