Sihe Steel
Sihe Steel
Engineered for extreme reliability, harsh industrial environments, and high-pressure system configurations.
For industrial environments operating between 427°C and 816°C, standard austenitic steels (such as 304) suffer from intergranular corrosion due to chromium carbide precipitation at grain boundaries. Grade 321 Stainless Steel bypasses this vulnerability through the precise addition of Titanium (Ti). Titanium exhibits a significantly higher chemical affinity for carbon than chromium, generating inert titanium carbides instead of chromium carbides.
This chemical stabilization ensures that the steel's structural chromium remains uniformly distributed, preserving critical corrosion resistance under long-term high thermal exposure. As a premier 321 Stainless Steel Seamless Tube Supplier, our manufacturing process yields seamless tubes with supreme mechanical stability, rupture strength, and low thermal creep.
Superior Intergranular Resistance: Ideal for non-annealed welded structures deployed in high-temperature zones.
Enhanced Creep & Rupture Limits: Excels under cyclic thermal stress compared to Grade 304 or 304L.
| Element/Spec | C (%) | Mn (%) | Si (%) | P (%) | S (%) | Cr (%) | Ni (%) | Ti (%) | Tensile Strength |
|---|---|---|---|---|---|---|---|---|---|
| 321 (UNS S32100) | ≤ 0.08 | ≤ 2.00 | ≤ 0.75 | ≤ 0.045 | ≤ 0.030 | 17.0 - 19.0 | 9.0 - 12.0 | 5x(C+N) to 0.70 | ≥ 515 MPa |
| 304 (UNS S30400) | ≤ 0.08 | ≤ 2.00 | ≤ 0.75 | ≤ 0.045 | ≤ 0.030 | 18.0 - 20.0 | 8.0 - 10.5 | — | ≥ 515 MPa |
| 316L (UNS S31603) | ≤ 0.030 | ≤ 2.00 | ≤ 0.75 | ≤ 0.045 | ≤ 0.030 | 16.0 - 18.0 | 10.0 - 14.0 | — | ≥ 485 MPa |
Established as a globally recognized expert and factory in China, Liaocheng Sihe Stainless Steel Material LTD operates six highly automated production lines specializing in high-tolerance stainless steel coiled tubes, polishing tubes, and seamless coiled tubing.
We adhere strictly to global manufacturing specifications, ensuring complete compliance with GB, ASTM, ASME, JIS, and EN standards. Our materials portfolio spans critical grades: 304/304L, 316L, 321, 317L, 309S, 310S, INCOLOY 800, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625.
By integrating world-class online Bright Annealing technology, we perform real-time, oxygen-free softening treatments. This results in an ultra-clean, mirror-finish inner and outer surface, ensuring maximum corrosion resistance and excellent mechanical ductibility for subsequent bending, coiling, and flanging.
Addressing complex engineering problems with custom metallurgical integrations.
Extreme offshore environments demand reliable subsea control umbilicals. Our continuous coiled tubing (lengths up to 10,000 meters / 32,800 feet) reduces the risk of orbital weld failures under deep ocean pressure.
High thermal exposure and mechanical vibrations require Titanium-stabilized Grade 321 tubes to resist fatigue and oxidation in engine combustion environments and exhaust manifolds.
Ultra-high purity (UHP) gas distribution pipelines benefit from our bright-annealed, electro-polished stainless steel tubing, minimizing mechanical particle accumulation and micro-leakage.
Evolving standard steels into superalloy complexes for next-generation industries.
With the surge in global green energy initiatives, hydrogen storage and delivery systems face the threat of "hydrogen embrittlement". Our chemical engineering lab is optimizing specialized Grade 321 modifications with elevated nickel limits and precise trace element compositions to maintain microstructural integrity at up to 700 bar pressure.
As deepwater exploration reaches depths exceeding 3,000 meters, control lines undergo high tension loads. Our technical path includes welding optimization for high-alloy coiled tubing like Incoloy 825 and Duplex 2205 to integrate high mechanical strength with outstanding localized pit-corrosion protection.
State-of-the-art custom processing tailored to exact structural layouts.
High-precision engineering of multi-dimensional coils and custom bend Radii for heat exchangers.
Precision drawing tolerances down to ±0.05 mm on the outer diameter and wall thickness.
Hydrostatic pressure tests, Eddy Current flaw inspection, and hardness verification.
Where safety, thermal endurance, and high corrosion protection are critical.
Exploring our specific production catalog formats and design elements.
Duplex 2205 and 316L high mechanical stability tubing configurations.
1/2 inch coiled tubes customized for petrochemical instrumentation systems.
High-temp structural resistance alloy coils manufactured by top-tier facilities.
Exporting to over 30 countries under certified quality management policies.
Liaocheng Sihe is globally authorized. We export heavy-duty coiled and seamless tubes to markets in the United States, Germany, Spain, South America, Southeast Asia, and Eastern Europe. Our compliance program provides extensive traceability.
Comprehensive solutions for procurement directors and engineers.
Our pricing is calculated based on raw nickel and chromium LME market indices, manufacturing tolerances, configuration sizes (e.g., continuous coils vs. straight tubes), and order quantities. Once your procurement team submits exact dimensions (OD, WT, Length) and standard specifications (e.g., ASTM A213 or EN 10216), we issue a comprehensive, fixed price schedule.
We require all international sea-freight orders to have a structural minimum order quantity to sustain efficient production line setups. For customized coiled tubing or specialty drawn dimensions, the minimum run varies from 500 meters to 1 ton depending on custom tooling requirements. Please contact our sales engineers for specific sizing trials.
Yes. We issue EN 10204 3.1 Mill Test Certificates (MTC) detailing complete chemical ladle analysis, mechanical properties (yield, tensile, elongation, hardness), and non-destructive test results (ultrasonic/hydrostatic/eddy current). Third-party inspections (SGS, TUV, BV) can also be coordinated prior to dispatch.
Our typical sample delivery time is 7 days. For large-scale manufacturing runs, lead times range between 20 to 30 days following receipt of deposit and final approval of shop drawing tolerances. Urgent requests can sometimes be integrated into active scheduled production runs.
We process export transactions via bank telegraphic transfer (T/T) and letters of credit (L/C). Standard arrangements require a 30% advance deposit to secure raw material alloys, with the remaining 70% balance payable against the presentation of the Bill of Lading (B/L) copy.
Coiled tubing is carefully wound on robust, reinforced iron or wooden spools, vacuum sealed, and enclosed in heavy-duty wooden crates to prevent moisture or mechanical deformation during transit. Straight tubes are bundled with protective ends and anti-corrosion oils. Our logistics systems ensure robust handling during long-distance maritime freight operations.
Corrosion-resistant materials engineered for petrochemical, structural, and mechanical applications.
