Sihe Steel
Sihe Steel
Explore our premium range of industrial-grade welded piping manufactured to meet strict international standards including ASTM, ASME, DIN, and JIS.
Your Trusted Global Partner in High-End Stainless Steel Manufacturing & Processing
Founded on a commitment to quality and engineering precision, Liaocheng Sihe Stainless Steel Material LTD is a premier manufacturer specializing in stainless steel coiled tubing, seamless coiled tubes, polished pipes, and super-long straight tubes. Operating six state-of-the-art production lines, we strictly execute our production processes under international criteria, including GB, ASTM, ASME, JIS, and EN.
Our material grade options span a broad chemical spectrum to address diverse industrial environments: from standard austenitic grades like 304/304L, 316L, 321, 317L, 309S, and 310S, to duplex and super-duplex alloys like 2205 and 2507, as well as ultra-durable nickel-alloy grades like Incoloy 825 and Inconel 625.
Our continuous online bright annealing technology allows for uniform recrystallization and structural softening of our tubes, delivering clean surfaces and outstanding mechanical properties. Today, more than 80% of our production output is exported globally, servicing high-spec industries in over 30 countries across North America, Europe, South America, and Asia.
A comprehensive technical deep-dive into the metallurgical configuration, chemical characteristics, and global supply dynamic of Grade 409 welded tubing.
Grade 409 (UNS S40900 / EN 1.4512) is a titanium-stabilized ferritic stainless steel. The addition of titanium (minimum 6 times the carbon/nitrogen content) suppresses sensitization during welding, preventing chromium carbide precipitation. This stabilization preserves the steel's basic corrosion resistance and mechanical integrity at high operating temperatures.
409 stainless steel is highly resilient to dry thermal scaling at temperatures up to 675°C under continuous service, and up to 815°C under intermittent cyclic exposures. The low coefficient of thermal expansion of the ferritic structure, compared to austenitic grades like 304, minimizes thermal fatigue and stress cracking in cyclic high-temperature applications.
Due to its lower chromium alloy content (10.5% to 11.75%) and lack of expensive nickel additions, 409 stainless steel acts as a highly cost-efficient upgrade from carbon steels and aluminized steels. It provides reliable defense against road salt, atmospheric carbonaceous exhaust condensate, and high-temperature moisture condensation.
Understanding the exact elemental boundaries and strength configurations allows design engineers to optimize wall thicknesses and piping diameters.
| Material Specification | C (%) | Mn (%) | Si (%) | Cr (%) | Ni (%) | Ti (%) | Tensile Strength (MPa) | Yield Strength (MPa) |
|---|---|---|---|---|---|---|---|---|
| ASTM A268 / A240 TP409 | 0.08 max | 1.00 max | 1.00 max | 10.50 – 11.75 | 0.50 max | [6x(C+N)] to 0.75 max | ≥ 380 | ≥ 170 |
| JIS G4305 SUH409L | 0.03 max | 1.00 max | 1.00 max | 10.50 – 11.75 | 0.60 max | [5x(C+N)] to 0.75 max | ≥ 360 | ≥ 175 |
How Liaocheng Sihe integrates advanced raw material sourcing, automated welding, and online bright annealing to maximize value for global buyers.
We implement a continuous hydrogen-reducing bright annealing method. Processing steel pipes through this online furnace under protective atmospheres softens the material, relieves welding stresses, and keeps the surfaces scale-free and mirror-finished, eliminating the need for post-treatment acid pickling.
To ensure 100% sound welds and leakproof performance, every production run is subjected to hydrostatic pressure testing, online eddy current examination, physical flattening, reverse bending, and pneumatic air tightness validation. Our zero-defect target ensures that all pipes shipped from Liaocheng Sihe withstand severe high-pressure environments.
Our production facilities support bespoke processing services, ranging from custom wall thicknesses (up to 3.0mm) to specialized diameter options. We offer continuous coiled tubing lengths up to 10,000 meters to minimize the need for orbital weld joints during installation in subsea or underground systems.
From deepwater oil and gas offshore operations to urban energy infrastructure, our engineered products solve critical corrosion and thermal issues.
Grade 409 is the foundational alloy for automotive catalytic converters, exhaust manifolds, mufflers, tailpipes, and exhaust structural hardware. Its resistance to heat and acidic combustion residues ensures longevity for vehicular emission systems.
Due to its high thermal conductivity and oxidation resistance in mildly corrosive atmospheres, 409-grade welded pipes are used for tube bundles, thermal preheaters, waste heat recovery systems, and incinerator components.
For chemical injection lines, hydraulic control networks, and subsea control umbilicals in extreme offshore oil and gas drilling, we customize super-long coiled tubing in premium duplex alloys (2205/2507) and nickel alloys (825/625) to provide high corrosion resistance and high-pressure integrity.
Used in residential and commercial cooling units where moisture, condensation, and temperature cycling cause rapid degradation of conventional carbon steels. Specifying 409 welded tubing extends system lifespans while minimizing equipment down-times.
Our mill certificates and laboratory accreditations are accepted worldwide, ensuring total conformity with global engineering standards.
In-depth insights into standardizing procurement routes, tracking chemical composition fluctuations, and optimizing logistic costs.
With regulations like Euro 6, US EPA Tier 3, and China VI, automotive OEMs must optimize exhaust systems to run hotter and cleaner. This requires reliable 409 and 439 welded piping suppliers to guarantee exact chemical compositions and tight weld seam tolerances, preventing critical gas leaks.
Purchasing departments are consolidating their raw material supply chains to reduce logistics costs and quality variability. Liaocheng Sihe acts as a comprehensive, single-source manufacturer, offering coiled pipes, straight pipes, precision capillary lines, and flat sheet materials.
With infrastructure and equipment service lifetimes extending from 10 to over 20 years, carbon steel piping is being replaced with ferritic and austenitic stainless steel grades. 409 welded tubing balances performance and initial capital costs, offering high ROI for global procurement agents.
Our services go beyond manufacturing standard sizes. We provide custom machining, precision cutting, and structural manipulation.
We bend, coil, and spiral form stainless steel pipes to meet your dimensional requirements. Our state-of-the-art tooling avoids wall thinning, micro-cracking, or cross-sectional distortion in small bend radii.
We provide ultra-straight pipes cut to precise lengths with clean, burr-free ends. Our automated laser-cutting tables handle various profiles and prep-weld bevel configurations to speed up your final assembly.
We offer specialized pipe end treatments including expanding, swaging, and flanging. These custom configurations simplify connections to manifolds and converters in automotive and industrial piping networks.
Our stainless steel tubes are utilized in key industries worldwide, delivering corrosion protection and reliable performance.
Find authoritative answers regarding pricing, materials, order quantities, delivery times, and customized design services.
Explore our core product ranges manufactured to high quality standards.
2205 duplex stainless steel containing austenitic and ferritic structures...
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1/2 stainless steel coiled tubing refers to a coil of stainless steel tubing...
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Premium quality high temperature furnace tube and heat exchanger coil production...
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Precision drawn capillary tubes for instrumentation, sensors and hydraulic control lines...
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Clean and bright surface finishes for decorative, chemical and sanitary uses...
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Custom size and thickness profiles designed specifically for heat transmission efficiency...
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Highly robust Incoloy 825 and Inconel 625 tubes for extreme acidic solutions...
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Dual phase microstructures offering higher tensile strength and pitting resistance...
VIEW MORE PRODUCTDiscover our extensive range of high-performance piping, sheets, and capillary lines designed for high-stress applications.
