ASTM A312 TP321H Stainless Steel Seamless Pipe
High-Temperature Stabilized Stainless Steel Pipes for Critical Service
We are the professional exporter and supplier of ASTM A312 TP321H Stainless Steel Seamless Pipe,X8CrNiTi18-10 seamless steel Pipes.
ASTM A312 TP321H seamless pipes are high-carbon, titanium-stabilized austenitic stainless steel pipes specifically designed for high-temperature and high-pressure applications. Manufactured in accordance with ASTM A312, TP321H pipes provide excellent resistance to intergranular corrosion, oxidation, and thermal fatigue, making them ideal for continuous elevated-temperature service.
ASTM A312 TP321H stainless steel seamless pipes are widely used in oil refineries, petrochemical plants, power generation facilities, and high-temperature process piping systems.
What Is ASTM A312?
ASTM A312 is the standard specification for seamless, welded, and heavily cold-worked austenitic stainless steel pipes intended for high-temperature and general corrosive service. It defines requirements for:
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Chemical composition
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Mechanical properties
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Heat treatment
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Dimensional tolerances
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Testing and inspection
Material Grade: TP321H Stainless Steel
TP321H is the high-carbon version of TP321, alloyed with titanium to stabilize carbon and prevent carbide precipitation during high-temperature exposure.
321H, is a titanium stabilized austenitic stainless steel that is known for its general corrosion resistance. This higher carbon version of Type 321 stainless steel offers a wide variety of benefits including: Excellent resistance oxidation to 1500°F (816°C) Good low temperature toughness.
Grade 321 is a titanium stabilized austenitic stainless steel with good general corrosion resistance. It has excellent resistance to intergranular corrosion after exposure to temperatures in the chromium carbide precipitation range of 800 – 1500°F (427 – 816°C). The grade resists oxidation to 1500°F (816°C) and has higher creep and stress rupture properties than grade 304 and 304L. It also possesses good low temperature toughness.
ASTM A312 TP321H is the higher carbon (0.04 – 0.10) version of the alloy. It was developed for enhanced creep resistance and for higher strength at temperatures above 1000oF (537°C). In most instances, the carbon content of the plate enables dual certification.
ASTM A312 TP321H Pipe specification
1. Material Grade: TP304 , TP304L , TP304H , TP316 , TP316L , TP316Ti , TP309S , TP310S , TP321 , TP321H , TP347 , TP347H , etc
2. Outer Diameter: 10.3mm-1219mm
Wall Thickness : 1.24mm-59.54mm
3. Length: Normally fixed length 6m , can as per customer’s requirement
4. Standard: ASTM A312 ; ASTM A358 ; ASTM A789 ; ASTM A790 ect .
ASTM A312 TP 321H STAINLESS STEEL PIPES CHEMICAL COMPOSITION
Typical compositional ranges for grade 321H stainless steels Pipes
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | Other | |
| 321 | min. max |
– 0.08 |
2.00 | 0.75 | 0.045 | 0.030 | 17.0 19.0 |
– | 9.0 12.0 |
0.10 | Ti=5(C+N) 0.70 |
| 321H | min. max |
0.04 0.10 |
2.00 | 0.75 | 0.045 | 0.030 | 17.0 19.0 |
– | 9.0 12.0 |
– | Ti=4(C+N) 0.70 |
ASTM A312 TP 321H STAINLESS STEEL PIPES MECHANICAL PROPERTIES
Mechanical properties of 321H grade stainless steel
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| 321 | 515 | 205 | 40 | 95 | 217 |
| 321H | 515 | 205 | 40 | 95 | 217 |
| 321H also has a requirement for a grain size of ASTM No 7 or coarser. | |||||
ASTM A312 TP 321H STAINLESS STEEL PIPES PHYSICAL PROPERTIES
Physical properties of 321H grade stainless steel in the annealed condition
| Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100°C (J/kg.K) | Electrical Resistivity (nΩ.m) | |||
| 0-100°C | 0-315°C | 0-538°C | at 100°C | at 500°C | |||||
| 321 | 8027 | 193 | 16.6 | 17.2 | 18.6 | 16.1 | 22.2 | ||
Heat Treatment
ASTM A312 TP321H pipes are supplied in solution annealed condition, ensuring optimal corrosion resistance and stable microstructure for high-temperature service.
TP321H vs TP321 vs TP347H Pipes
| Item | TP321 | TP321H | TP347H |
|---|---|---|---|
| Carbon Content | Low | High | High |
| Stabilizing Element | Ti | Ti | Nb |
| High-Temp Strength | Good | Better | Excellent |
| Typical Use | General service | Continuous high-temp | Severe high-temp |
How to order the ASTM A312 TP 321H STAINLESS STEEL PIPES?
Example#1,
ASTM A312 TP 321H STAINLESS STEEL PIPE, 10 Inch, Schedule 40S, Bevelled End, length 6M.
ASTM A312 TP321H stainless steel seamless pipes deliver excellent high-temperature strength, oxidation resistance, and long-term reliability for critical pressure piping systems. Fully compliant with ASTM A312, TP321H pipes are a proven solution for refineries, power plants, and high-temperature industrial applications.
