Sihe Steel
Sihe Steel
In modern high-temperature industrial processes, selecting materials capable of maintaining structural integrity and oxidation resistance is critical. Stainless steel Grade 310S (UNS S31008 / EN 1.4845) is a highly alloyed austenitic stainless steel engineered for service in extreme environments. Unlike standard 304 or 316 grades, 310S contains a high chromium (24% to 26%) and nickel (19% to 22%) profile. This chemical composition allows the metal to resist oxidation at continuous temperatures up to 1035°C (1900°F) and cyclic temperatures up to 1040°C in air.
The "S" in 310S denotes a lower carbon content (maximum 0.08%), which significantly reduces the risk of chromium carbide precipitation at grain boundaries during welding or prolonged exposure to high temperatures (the sensitization temperature range of 425°C to 815°C). Consequently, 310S capillary tubing displays superior mechanical strength, creep resistance, and corrosion-resistance characteristics, making it the material of choice for industrial furnace parts, gas turbine exhausts, and heat exchanger equipment.
| Element | Chromium (Cr) | Nickel (Ni) | Carbon (C) | Manganese (Mn) | Silicon (Si) | Phosphorus (P) | Sulfur (S) | Iron (Fe) |
|---|---|---|---|---|---|---|---|---|
| Percentage (%) | 24.00 - 26.00 | 19.00 - 22.00 | ≤ 0.08 | ≤ 2.00 | ≤ 1.50 | ≤ 0.045 | ≤ 0.030 | Balance |
The high silicon content (≤ 1.50%) acts as an additional barrier against high-temperature oxidation by forming a silica scale beneath the chromium-rich oxide film. This double-layer protective mechanism provides excellent resistance in carburizing and reducing environments, commonly found in petrochemical reforming furnaces and synthesis gas lines.
Procurement of high-performance 310S capillary tubes requires an understanding of both local industrial standards (such as ASTM, ASME, EN, JIS, and GB) and the application-specific mechanical limits. Modern B2B sourcing agents prioritze metallurgical traceability, surface finish quality (internal and external roughness, commonly measured as Ra values), and dimensional tolerance compliance.
Global supply chain vulnerabilities in the post-pandemic era have shifted procurement models from a purely price-driven approach to a resilience-first and quality-first model. High-precision capillary tubing is used in critical nodes of industrial systems; a minor failure in an umbilical coiled tubing line deployed in deep-sea petroleum extraction can result in millions of dollars in downtime and severe environmental hazards.
To mitigate these procurement risks, global enterprises are establishing strategic partnerships with integrated manufacturers who can provide comprehensive verification documentation, including chemical mill test certificates (MTRs), hydrostatic test results, and non-destructive eddy current testing records.
The transition of Chinese stainless steel manufacturing into the Industry 4.0 paradigm has repositioned domestic mills as leading suppliers of precision components. By integrating automated drawing machines, continuous online bright annealing furnaces, and real-time digital dimensional monitoring systems, Chinese factories offer an optimal balance of cost-efficiency and technical precision.
Liaocheng Sihe Stainless Steel Material LTD is at the forefront of this industrial transformation. Operating three specialized production lines with a ten-year history of dedicated research, the factory utilizes advanced online bright annealing technology. In traditional manufacturing, heat treatment in normal atmospheres leads to surface oxidation (scale formation), requiring subsequent acid pickling that can degrade the dimensional integrity and inner surface finish of thin-walled capillary tubes.
By contrast, Liaocheng Sihe’s bright annealing process takes place in a highly controlled, dry hydrogen atmosphere, ensuring that the tubes remain oxidation-free and retain their bright, reflective, and smooth finish inside and out.
Equipped with compression, flaring, bending, 100% tensile strength testing, and air tightness chambers to ensure zero-defect dispatches to global buyers.
From raw material sourcing of premium steel billets (316L, 310S, Incoloy 825, Inconel 625) to final spooling and export logistics management.
Capable of executing high-precision drawings with outer diameter tolerances within ±0.02 mm and wall thickness tolerances within ±0.01 mm.
Design engineers must carefully verify the correlation between pressure limits, temperature ranges, and dimension calculations (using Lame’s equations for thick-walled cylinders or Barlow's formula for thin-walled lines) when specifying 310S capillary tubing.
Liaocheng Sihe Stainless Steel Material LTD produces high-performance coiled and capillary tubing within the following technical dimensions:
| Alloy Grade | Max Service Temp (Air) | Primary Corrosion Environment Resistance | Key Applications |
|---|---|---|---|
| SUS 310S | 1035°C (1900°F) | High-temperature oxidation, carburization, moderately reducing atmospheres | Furnace tubes, heat exchangers, industrial exhausts, petrochemical heaters |
| 316L | 850°C (1560°F) | Chloride-induced pitting, general atmospheric corrosion | Marine, pharmaceutical biotechnology, chemical process lines |
| Duplex 2205 | 300°C (572°F) | Stress Corrosion Cracking (SCC), severe localized pitting | Offshore oil & gas, chemical processing plants, marine systems |
| Incoloy 825 | 540°C (1000°F) | Sulfuric & phosphoric acids, chloride-induced stress corrosion | Chemical scrubbers, oil and gas extraction, nuclear fuel processing |
| Inconel 625 | 980°C (1800°F) | High-pressure fatigue, severe acids, seawater pitting and crevice corrosion | Aerospace instrumentation, subsea control lines, gas turbines |
The versatility of stainless steel and nickel alloy capillary tubes makes them indispensable across a wide variety of industrial verticals. Below are the key sectors utilizing these precision engineered solutions:
In deep-water oil and gas operations, control signals, chemical inhibitors, and hydraulic fluids are transmitted through long-length umbilical lines. Using materials like Super Duplex 2507, Alloy 825, or Alloy 625 coiled tubing ensures excellent resistance to seawater crevice corrosion, structural fatigue, and internal pressure levels. The lack of orbital welds in lengths up to 32,800 feet minimizes the potential for leakages, thereby ensuring high operational reliability.
The production of integrated circuits requires high-purity gas delivery systems. 316L and similar high-grade stainless steel capillary tubes must possess ultra-smooth internal surfaces (electropolished or bright annealed) to prevent particulate contamination, gas adsorption, and chemical reactions with reactive gases.
Liaocheng Sihe Stainless Steel Material LTD is a leading expert in the manufacturing and distribution of premium stainless steel coiled tubes, precision polishing tubes, and seamless coiled tubing. Operating six advanced production lines in China, we manufacture our products in strict accordance with global standards, including GB, ASTM, ASME, JIS, and EN.
Our standard product range covers diverse steel grades: 304/304L, 316L, 321, 317L, 309S, 310S, INCOLOY800, Austenitic steel 316L, Duplex 2205, Super Duplex 2507, Incoloy 825, and Inconel 625 series. We cater to high-stakes applications in military systems, semiconductor fabs, pharmaceutical biotechnology, precision instrumentation, hydraulic mechanisms, chemical reactors, power generation boilers, heat exchangers, aerospace structures, automotive assemblies, marine construction, air-conditioning units, and solar arrays.
To ensure complete safety in deeper, harsher offshore and subsea fields, we specialize in supplying corrosion-resistant materials for umbilical coiled tubing. We prioritize safety, high reliability, and custom sizing requests, serving clients across more than 30 countries, including the United States, Germany, Spain, South America, Southeast Asia, the Middle East, and Eastern Europe.
Our factory operations and product qualities are validated by authoritative international certification bodies. Below are our official quality certificates:
Explore our wide manufacturing portfolio. We support customization of dimensions and mechanical properties to fit specific engineering needs:
Duplex 2205 and 2507 stainless steel containing austenitic and ferritic structures, optimized for subsea umbilical control lines.
1/2 inch stainless steel coiled tubing refers to a coil of stainless steel tubing designed for heavy industrial fluid transfer.
Manufactured by dedicated factories in China for application in high-temperature heat exchangers and furnaces.
Here are comprehensive answers to frequently asked technical and commercial questions. If you require further engineering consultations or an updated pricelist for 310S capillary tubing, please contact our technical sales team directly.