SS 321 seamless pipes can withstand intermittent service up to 900°C (1652°F) and continuous service temperatures up to 925°C (1697°F).
ASTM A312 Stainless Steel 321 Seamless Pipe Manufacturer
We at Xintongda Special Steel are a leading manufacturer of stainless steel 321 seamless pipes in China. Our stainless steel 321 pipes are titanium-stabilised austenitic stainless steel products. These contain 17-19% chromium, 9-12% nickel, 0.08% carbon (max), and a controlled titanium addition (Ti ≥ 5×C, max 0.70%). These pipes are manufactured using advanced cold-forming and hot-finishing methods that meet ASTM A312, EN, JIS, and GB standards. The material has strong intergranular corrosion resistance, outstanding creep strength, and consistent oxidation resistance in high-temperature operating conditions. These properties make our SS 321 seamless pipes ideal for aerospace systems, petrochemical refineries, heat exchangers, and furnace components. With an annual manufacturing capacity of 25,000 tons and well-maintained stock, we ensure efficient global supply and fast delivery of orders of any size. All our pipe products have been thoroughly tested and certified to international quality standards, ensuring total traceability and long-term service reliability.
Standards and specifications covered:
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Standard
ASTM A312
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OD Range
6-1016 mm
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Thickness
1-65 mm
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Length
≤ 18 m
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Technical Data
Technical Data
SS 321 Seamless Pipe Manufacturing Process
Our 321 seamless stainless steel pipe is manufactured using a precise method that begins with premium raw materials. The process continues with piercing and rolling to form the hollow shell. The procedure ends with a controlled heat treatment and extensive testing to yield the final seamless, high-performance product.
Key Features of 321 Stainless Steel Pipe
ASTM A312 TP321 stainless steel seamless pipes have 4 features. These include corrosion resistance, high temperature strength, resistance to intergranular attack, and oxidation resistance. The material ensures stability and durability under extreme conditions.
- Corrosion Resistance: Our SS 321 pipes exhibit exceptional resistance to oxidation and intergranular corrosion due to the chromium-rich composition and titanium stabilisation.
- High-Temperature Strength: The addition of titanium makes this grade extremely durable at high temperatures. The austenitic stainless steel grade maintains its mechanical integrity and strength, functioning well at temperatures up to 925°C (1697°F) for continuous service, where non-stabilised grades can fail.
- Excellent Resistance to Intergranular Corrosion: The titanium-stabilised composition is crucial in preventing carbide precipitation during welding or high-temperature exposure. This stabilisation binds the carbon, stopping the chromium depletion at grain boundaries and thus offering outstanding protection against intergranular corrosion.
- Good Oxidation Resistance: The alloy’s chromium-rich composition enables the formation of a stable oxide layer. This film is highly resistant to scale and oxidation, allowing it to tolerate repeated temperature cycles, and extended service in hot, oxidising environments.
ASTM A312 TP321 Pipe Equivalent Material
The ASTM A312 TP321 grade is a well-known and widely used standard around the globe. The UNS S32100 / DIN 1.4541 designation is the primary equivalent for this grade. It is a widely accepted material across high-temperature industrial applications.
| GRADE | UNS | GB | JIS | ISO | DIN/EN | GOST | |
| ISC | NEW | ||||||
| 321 | S32100 | S32168 | 06Cr18Ni11Ti | SUS321 | X6CrNiTi18-10 | 1.4541 | 08X18H10T |
100% Certified Testing & Documentation
- EN 10204 3.1 and EN 10204 3.2 Material Test Certificates (MTC)
- Raw Materials Certificate
- 100% PMI (Positive Material Identification)
- Heat Treatment Charts
- Third-Party Inspection Report
- Surface roughness and size measurement
- Manufacturer Test Certificate
- Laboratory Test Certificate from the Government-Approved Lab
Industrial Applications of UNS S32100 Seamless Pipes
ASTM A312 TP321 stainless steel pipe has 7 key industrial applications that need high temperatures, thermal cycling and corrosion resistance. This grade is commonly used in equipment and systems that are subjected to continuous heat due to its titanium-stabilised structure. The uses for stainless steel 321 seamless pipe are listed below.
Aircraft Exhaust Manifolds
ASTM A312 TP321 seamless pipes are mainly used in aircraft exhaust manifolds, as they can handle high temperatures. The material exhibits resistance to oxidation and thermal fatigue, which ensures an extended service life under repeated cycles of heating and cooling.
Expansion Joints
321 stainless steel pipe is used for expansion joints in places where thermal movement is common. Its stability at high temperatures contributes to strength and flexibility without cracking or distortion.
Bellows
SS 321 seamless pipe is ideal for bellows due to its strong resistance to heat stress and vibration. This makes it reliable for systems exposed to high temperatures and pressure variations.
Furnace Parts
We use this pipe in components such as radiant tubing and protective sleeves, within furnaces. It is suitable for long-term exposure to furnace heat due to its exceptional high-temperature durability and scaling resistance.
Heating Element Tubing
ASTM A312 TP321 pipe is used as protective sheathing for heating elements. It safeguards internal components against oxidation, while preserving structural integrity under high operating temperatures.
Heat Exchangers
Steel 321 seamless pipe is extensively used in heat exchangers that process hot gases or fluids. Its resistance to intergranular corrosion increases reliability, and it reduces the maintenance requirements in high-temperature service.
Woven or Welded Screens for High-Temperature Mineral Processing
321 pipes are used in the mineral processing industry to protect woven or welded screens against heat and corrosion. During extended periods of high-temperature operation, the alloy maintains its strength and surface stability.
Frequently Asked Questions
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What temperature can SS 321 seamless pipe withstand?
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What surface finishes are available for SS 321 seamless pipes?The most common surface finishes for SS 321 seamless pipes include pickled and annealed (AP), bright annealed (BA), and polished finishes, ranging from standard mill finish to various grit polishes.
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Is SS 321 seamless pipe cost-effective?Yes, the SS 321 seamless pipe is a cost-effective option for high-temperature and corrosive applications due to its higher lifespan and resilience, which reduces the need for regular repairs and maintenance.
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What is the difference between 304 and 321 SS seamless pipes?The key difference is that 321 SS seamless pipe contains titanium, which reduces sensitisation and intergranular corrosion after welding, making it superior to 304 in the sensitization temperature range of 425–815°C, where non-stabilized grades are vulnerable to intergranular corrosion.