Sihe Steel
Sihe Steel
Select industrial products engineered for high-pressure, high-temperature, and corrosive environments.
Incoloy 825 is a nickel-iron-chromium alloy with additions of molybdenum, copper, and titanium. Developed specifically to provide exceptional resistance to both reducing and oxidizing acids, it bridges the performance gap between conventional austenitic stainless steels (such as 316L) and specialized high-nickel superalloys.
The nickel content, typically ranging between 38% to 46%, provides exceptional immunity to chloride-induced stress corrosion cracking (SCC)—a classic failure mode for lower alloy steels in offshore marine environments. The chromium (19.5% to 23.5%) content ensures a robust passivation layer that guards against oxidizing mediums, while the addition of molybdenum (2.5% to 3.5%) works synergistically with chromium to raise the alloy's Pitting Resistance Equivalent Number (PREN), defending against crevice and pitting attacks in saline waters.
Moreover, titanium addition (0.6% to 1.2%) acts as a stabilizing agent. Titanium binds with carbon during heat treatments to form titanium carbides, preventing the precipitation of chromium carbides at grain boundaries. This stabilization prevents intergranular corrosion (sensitization) after welding or when exposed to the sensitizing temperature range of 650°C to 760°C.
| Element | Standard Range (%) |
|---|---|
| Nickel (Ni) | 38.0 - 46.0% |
| Iron (Fe) | Balance (min. 22.0%) |
| Chromium (Cr) | 19.5 - 23.5% |
| Molybdenum (Mo) | 2.5 - 3.5% |
| Copper (Cu) | 1.5 - 3.0% |
| Titanium (Ti) | 0.6 - 1.2% |
The operational expansion of Incoloy 825 capillary tubing across global energy and analytical fields.
As petroleum extraction moves into deeper waters (>3,000 meters), subsea umbilical systems require hydraulic and chemical injection lines capable of withstanding external hydrostatic pressures up to 15,000 psi. 825 capillary tubing serves as the core fluid conduit, preventing failures caused by sour gas environments ($H_2S$ and $CO_2$) and high temperatures.
High-Performance Liquid Chromatography (HPLC) and analytical gas chromatographs require micro-bore capillary lines with precise interior dimensional tolerances (inner diameter finishes down to Ra < 0.4 μm). The inertness of Incoloy 825 ensures zero sample contamination and no reaction with active chemical reagents.
Due to geopolitical and cost pressures, global engineering firms are shifting from traditional European factories to certified Chinese manufacturers. The target is to find suppliers who can deliver continuous long coils (up to 10,000 meters without orbital welds) while complying with stringent ASTM A269 and ASTM B704 standards.
Based in China, Liaocheng Sihe Stainless Steel Material LTD is a world-class manufacturing facility specialized in producing cold-drawn seamless coiled tubing and precision capillary pipes. Operating six advanced production lines, the factory strictly adheres to global quality parameters, utilizing state-of-the-art technologies to satisfy stringent demands from over 30 countries and regions including the United States, Germany, Spain, South America, Southeast Asia, the Middle East, and Eastern Europe.
The cornerstone of Liaocheng Sihe's technological leadership is the introduction of world-class online bright annealing technology. Unlike conventional air annealing, which requires subsequent acid pickling (leaving a rough surface profile), bright annealing takes place under a controlled hydrogen gas protective atmosphere. This thermal process yields a perfectly soft, ductile steel matrix with an exceptionally clean, scale-free inner and outer surface finish.
Liaocheng Sihe supports multi-alloy processing, offering options in Austenitic steel 304/304L, 316L, 321, 317L, 309S, 310S, and Super-Austenitic Incoloy 800, along with high-end Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625. This versatility permits the factory to deliver specialized answers across varied industrial niches.
Proven capability and production metrics for high-demand global markets.
Providing high-precision modification and customization for heavy industrial demands.
We support various materials including 304, 316L, 2205, Incoloy 825, and Inconel 625, with specialized specifications (diameters ranging from 6.35 mm to 19 mm) designed specifically for long coiled installations.
Precision execution of bending, custom spiral coiling, and precision cold drawing. Perfect for space-constrained industrial systems and complex heat exchangers.
Equipped with advanced laser cutting, mechanical circular saw cutting, and high-efficiency straightening lines to ensure exact lengths with square, burr-free ends.
We continuously implement state-of-the-art passivation and mechanical polishing procedures to reduce internal surface roughness, critical for biochemical and flow control systems.
Our capabilities include custom end-flanging, flaring, and expansions, matching standard fittings for safe assembly in chemical processing and exhaust system lines.
Non-destructive test suites are integrated into our production path: eddy current inspection, hydrostatic testing, hardness check, tensile strength testing, and air tightness checks.
Where reliability, corrosion resistance, and micro-precision fluid flow are vital.
Tested, traced, and certified to meet extreme environments and international engineering protocols.
Liaocheng Sihe is committed to providing materials backed by full documentation. Our facilities follow standards set by ASTM B704 for alloy coiled tubing, ASTM A269 for seamless and welded tubing, and equivalent JIS/DIN metrics. Every delivery is traceable back to the raw material heat charge.
Answers to critical sourcing questions, metallurgy inquiries, and logistical coordination.
Supporting your project demands with heat exchanger tubes, plates, and varied steel alloys.
