ASTM A312 TP321/321H Seamless Pickled And Annealed Pipe
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What is the ASTM A312 standard?
ASTM A312 is the standard specification for seamless, welded, and heavily cold-worked austenitic stainless steel pipes designed for high-temperature and general corrosive service. It is commonly synonymous with ASME SA312 and covers popular grades like TP304/304L and TP316/316L, widely used in chemical, oil and gas, and food processing industries.
Supplier of ASTM A312 TP321/321H Seamless Pipe
GNEE supplies seamless pickled and annealed pipes in compliance with ASTM A312 TP321/321H (UNS S32100/S32109). These pipes are manufactured through advanced processes including three-roll cross rolling, extrusion, and sizing, followed by a controlled annealing treatment. During annealing, the pipes are held at 950–1120°C and then rapidly cooled to eliminate internal stresses. Subsequent degreasing, pickling, and passivation effectively remove surface oxide scale and impurities, ensuring a clean and corrosion-resistant finish.Compared to TP321, TP321H stainless steel pipes offer significantly enhanced high-temperature performance, with creep rupture strength increased by over 25%. At 800°C continuous service, oxidation weight gain remains below 2 mg/cm², and the material is suitable for long-term use at temperatures up to 850–925°C.
ASTM A312 TP321 stainless steel pipes are relatively easy to form and draw, although they require higher forming forces and may exhibit greater springback compared to ferritic stainless steels and carbon steels. The material work-hardens rapidly during processing, and annealing is recommended after severe forming operations to restore ductility.
GNEE offers TP321 stainless steel pipes with an outer diameter range of 6.0 mm to 914.4 mm (1/4" to 36") and wall thickness from 0.5 mm to 50 mm (SCH 5 to XXS). We also provide value added processing services such as cutting, beveling, and bending. Each batch is supplied with an EN 10204 3.1 Mill Test Certificate (MTC), and additional inspections including hydrostatic testing, PMI (Positive Material Identification), and third-party inspections (such as SGS or BV) can be arranged upon request.
ASTM A312 TP 321 / 321H Stainless Steel Pipes Specifications
| Specifications | : | ASTM A 312 / ASME SA 312 |
|
Dimensions |
: | ASTM, ASME and API |
| SS 321 / 321H Pipes | : | 1/2″ NB – 16″ NB |
| ERW 321 / 321H Pipes | : | 1/2″ NB – 24″ NB |
| EFW 321 / 321H Pipes | : | 6″ NB – 100″ NB |
| Size | : | 1/8″NB TO 30″NB IN |
| Specialized in | : | Large Diameter Size |
| Schedule | : | SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120, SCH140, SCH160, XXS |
| Type | : | Seamless / ERW / Welded / Fabricated / LSAW Pipes |
| Form | : | Round, Square, Rectangular, Hydraulic Etc |
| Length | : | Single Random, Double Random & Cut Length. |
| End | : | Plain End, Beveled End, Treaded |
ASTM A312 TP321 chemical composition
| Element | TP321 (UNS S32100) | TP321H (UNS S32109) |
| Carbon (C) | 0.08 max | 0.04 - 0.10 |
| Manganese (Mn) | 2.00 max | 2.00 max |
| Phosphorus (P) | 0.045 max | 0.045 max |
| Sulfur (S) | 0.030 max | 0.030 max |
| Silicon (Si) | 1.00 max | 1.00 max |
| Chromium (Cr) | 17.0 - 19.0 | 17.0 - 19.0 |
| Nickel (Ni) | 9.0 - 12.0 | 9.0 - 12.0 |
| Titanium (Ti) |
5×(C+N)min, 0.70 max |
4×C min, 0.70 max |
Mechanical Properties
| Property | Requirement |
| Tensile Strength |
≥ 515 MPa (75 ksi) |
| Yield Strength ( 0.2% Offset) |
≥ 205 MPa (30 ksi) |
| Elongation ( in 2 in. or 50mm) |
≥ 35% |
| Hardness (Brinell / Rockwell B) |
≤ 192 HBW / 90 HRB |
321 SS Heat Treatment & Delivery Condition
| Parameter | Description |
| Solution Temperature (TP321) |
≥ 1040°C (1900°F), rapid cooling |
| Solution Temperature (TP321H) |
≥ 1095°C (2000°F) for grain size control |
| Pickling | Full immersion in nitric-hydrofluoric acid solution |
| Stabilizing Heat Treatment | Optional, usually 845°C - 900°C (1550°F - 1650°F) |
SS 321H Seamless Pipe Equivalent Material Grade
| STANDARD | WERKSTOFF NR. | UNS | JIS | EN |
| SS 321 | 1.4541 | S32100 | SUS 321 | X6CrNiTi18-10 |
| SS 321H | 1.4878 | S32109 | SUS 321H | X12CrNiTi18-9 |
SS 321 Pipe Applications
Petrochemical: Refinery piping, heat exchangers, and furnace parts.
Aerospace: Exhaust systems and engine components.
Power Generation: Superheater tubes and boiler components.
What is the difference between A312 and A213?
ASTM A312 applies to pipes (nominal diameter, primarily used for fluid transport), while ASTM A213 applies to tubing (precise outer diameter and wall thickness, primarily used for heat exchangers and boilers). Their dimensional tolerances differ.
TP321 seamless pipe price per kg
The price of TP321 stainless steel seamless pipe typically ranges from $1.00 to $5.00 per kilogram, but prices vary depending on size, wall thickness, and supplier. Bulk purchases are usually more cost-effective, with some bulk prices reaching $1,000 to $2,500 per ton (or $1.00 to $2.50 per kilogram).
ASTM A312 TP321 Seamless Pipe Testing and Quality Assurance
TP321 pipes undergo rigorous testing to ensure compliance with ASTM A312 standards:
Non-Destructive Testing (NDT): Includes hydraulic testing, ultrasonic testing, or eddy current testing to detect internal and surface defects.
Mechanical Tests: Tensile, hardness, and flattening tests to verify mechanical properties.
Chemical Analysis: PMI (Positive Material Identification) and spectrometry to confirm composition.
Corrosion Tests: Intergranular corrosion tests (e.g., ASTM A262) to ensure resistance to sensitization.
To ensure the integrity of ASTM A312 TP321/321H steel pipes, we employ rigorous packaging: each pipe is equipped with a plastic end cap and individually wrapped in polyethylene film to protect the pickled surface. The pipes are securely bundled (maximum load capacity 2000 kg) and packed in IPPC-certified plywood crates suitable for sea transport to prevent surface scratches and seawater corrosion. Each pipe bears indelible markings (size, grade, heat number, ASTM A312) and is accompanied by a double-layered waterproof label for 100% traceability.
