A stainless steel 321H seamless tube is a high-carbon, titanium-stabilised austenitic steel tube that has no weld seams. This alloy, also known as UNS S32109, provides enhanced creep strength and resistance to intergranular corrosion at temperatures above 538°C. It is one of the many grades of austenitic stainless steel tubes.
ASTM A213 Stainless Steel 321H Seamless Tube Manufacturer
We at Zhejiang Xintongda Special Steel (XTD) are a trusted manufacturer in China and a global supplier of 321H seamless tubes. The stainless steel 321H tube, also known as the TP321H seamless tube, is a titanium-stabilised austenitic stainless steel. It is primarily composed of chromium (17-19%) and nickel (9-12%). The "H" in the grade indicates a higher carbon content (0.04-0.10%) for better high-temperature strength and creep resistance compared to standard grades. Our products are manufactured using advanced cold-drawing and cold-rolling methods to ensure uniform grain structure and consistent wall thickness according to the ASTM A213, A269, A511, and EN10206-5 standards. Our 321H stainless steel tube performs well in tough conditions where it needs to resist rust, oxidation and high temperatures. These tubes are used in boilers, heat exchangers, superheaters, petrochemical units, refineries and power plants. As a company holding multiple international certifications with over 4 decades of experience, we have a supply capacity of 25,000 tonnes and can deliver in-stock products in a one-week lead time and production orders in 15-60 days.
Product specifications:
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Standard
ASTM A213
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OD Range
6.35-257 mm
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Thickness
0.89-12.7 mm
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Length
≤ 22 m
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Technical Data
Technical Data
321H Stainless Steel Tube Manufacturing Process
The manufacturing procedure of the 321H stainless steel tube starts by piercing a solid billet of the alloy through a hollow shell. After that, the shell undergoes hot working and cold drawing to attain the specified dimensions. Following this, solution annealing is conducted to preserve the corrosion-resistant properties. The tube is then subjected to pickling and straightening processes to achieve an oxide-free surface finish. We make sure that the quality of the tube is checked to confirm compliance with ASTM standards. Visit our official website to obtain further information regarding the manufacturing process.
What are the Key Features of 321H Stainless Steel Tubes?
Our ASTM A213 stainless steel tube offers 4 key features, which make it suitable for high-temperature industrial applications.
- Titanium stabilised: The chemical composition includes titanium at a minimum ratio of 4×(C+N), up to 0.70% max per ASTM A213, which binds with carbon and nitrogen during high-heat exposure. This stabilisation prevents chromium carbide precipitation, ensuring the metal resists intergranular corrosion after welding or thermal processing.
- Good oxidation resistance: This grade preserves a protective surface layer of chromium oxide when exposed to oxygen at high temperatures. The alloy is highly resistant to scaling and surface degradation, enhancing the service life of tubes during continuous heating cycles.
- High-temperature performance: The "H" grade denotes a higher carbon content, which enhances its creep strength and tensile qualities. This feature enables the tube to withstand permanent deformation under constant load at temperatures exceeding 538°C.
- Corrosion resistance: This material offers exceptional resistance to organic acids and aqueous solutions, in addition to maintaining stability at elevated temperatures. Specifically, the addition of titanium protects the structure from polythionic acid stress corrosion cracking, which frequently occurs in refinery environments.
ASME SA213 TP321H SS Tube Equivalent Material
Our ASME SA213 TP 321H stainless steel's primary equivalent designation is UNS S32109. It also meets international equivalents such as JIS SUS321H and EN/DIN 1.4878.
| GRADE | UNS | GB | JIS | ISO | DIN/EN | GOST | |
| ISC | NEW | ||||||
| 321H | S32109 | S32169 | 07Cr19Ni10Ti | SUS321HTP | X10CrNiTi18-10 | 1.4878 | 12X18H10T |
100% Certified Testing & Documentation
- EN 10204 3.1 and EN 10204 3.2 Material Test Certificates (MTC)
- Raw Materials Certificate
- 100% PMI
- Heat Treatment Charts
- Third-Party Inspection Report
- Surface roughness and size measurement
- Manufacturer Test Certificate (Impact Testing, Flattening, Flare, Bend, Hardness, Intergranular, Pitting Corrosion, Grain size, ET, UT, HT)
- Laboratory Test Certificate from the Government-Approved Lab
What Industries commonly use SS 321H Seamless Tubes?
We provide our Stainless Steel 321H Seamless Tube to 5 major industrial sectors.
Food processing
We supply these tubes for thermal processing equipment in food plants. The titanium stabilisation ensures the metal remains non-reactive during high-temperature sterilisation. Our tubes deliver excellent corrosion resistance for high-temperature food processing equipment
Power generation
We deliver these components for use in boiler superheaters and reheater sections. The high carbon content provides necessary creep strength for service above 538°C. This prevents pipe deformation under extreme thermal stress.
Oil and gas
Refineries install our tubes in flare headers and catalytic cracking units. The alloy prevents polythionic acid stress corrosion cracking in high-heat environments. These tubes maintain structural integrity when exposed to aggressive refinery gases.
Chemical processing
We supply this grade to chemical manufacturers for high-heat reactor vessels and transport piping. Our tubes are specified for processes where sensitisation might cause intergranular corrosion.
Aerospace
We provide high-quality tubes for high-temperature industrial exhaust systems. These components withstand intense thermal shock and high-velocity gas flows. The oxidation resistance maintains reliable performance at high-temperature exhaust and thermal management systems.
Frequently Asked Questions
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What is a stainless steel 321H seamless tube?
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How does Stainless Steel 321H Tube compare to 304 and 316 tubes?Stainless Steel 321H tubes provide more strength at high temperatures compared to 304 and 316 grades. The titanium stabilisation prevents carbide precipitation over prolonged temperature exposure. Compared to 316, it has lower chloride corrosion resistance, but it is more reliable in continuous high-temperature applications.