ASTM A312 TP321 High Pressure Stainless Steel Tubing

Our manufactured ASTM A312 TP321 stainless steel pipes pass the ASTM A262 intergranular corrosion test. After pickling and passivation, they exhibit no obvious pitting corrosion within 48‑72 hours in 5% NaCl salt‑spray environment. Their resistance to intergranular corrosion after welding is significantly better than that of 304, delivering favorable corrosion‑resistant performance.

Besides, they can operate continuously at 430‑650 °C with a maximum intermittent oxidation‑resistant temperature of 870 °C, making them suitable for high‑temperature thermal‑cycle working conditions with good high‑temperature resistance.

Furthermore, our ASTM A312 TP321 stainless steel pipes feature tensile strength ≥515 MPa, yield strength ≥205 MPa and elongation ≥35%. They possess good toughness and excellent weldability. With Ti ≥5×(C+N), they inhibit intergranular corrosion caused by welding and require no on‑site solution annealing after welding.

GNEE Value‑Added Services：

1. Precision length cutting, chamfered/mitered‑end processing

2. Surface treatments including pickling & passivation, bright annealing, etc.

3. Custom non‑standard outer diameters, wall thicknesses, square / rectangular pipes.

 A312 TP321 SS Square tube

 A312 TP321 High Pressure SS tube 

 A312 TP321 Pickled  Pipes

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Specifications of A312 TP321 SS Pipe 

Chemical Composition 

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

 

Mechanical Properties 

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

 

Physical Properties 

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (m/m/0C)			Thermal Conductivity (W/m.K)
			0-1000C	0-3150C	0-5380C	at 1000C	at 5000C
321	8027	193	16.6	17.2	18.6	16.1	22.2

 

Grade specifications 

Grade	UNS No	Old British		Euronorm		Swedish SS	Japanese JIS
		BS	En	No	Name
321	S32100	321S31	58B, 58C	1.4541	X6CrNiTi18-10	2337	SUS 321

 

Price Reference

Product Type	Indicative FOB Price (USD/kg)
TP321 welded pipes (pickled, standard SCH)	1.8‑3.2
TP321 seamless pipes (pickled, standard SCH)	2.6‑5.0
Thin‑wall precision / heavy‑wall XXS pipes	4.2‑8.0
Polished finish & non‑standard custom sizes	+0.4‑1.2

 

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Quality Inspection 

We implement full‑process and multi‑dimensional quality control. Raw materials are subject to PMI spectral composition analysis. Finished products undergo hydrostatic test as well as eddy current / ultrasonic flaw detection to identify internal defects such as cracks and pores. Sampling inspections are carried out for outer diameter, wall thickness tolerance and surface quality. EN10204 3.1/3.2 material test certificates are available for each batch. Third‑party re‑inspection is accepted with full traceability of quality.

 

 

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High‑quality packaging

Adopt seaworthy‑grade export packaging: rubber end caps for pipe ends, VCI anti‑rust paper, waterproof film, together with fumigated wooden crates to resist salt spray and moisture in marine transportation and ensure intact condition during long‑distance shipment.

 

Moisture‑proof packaging

Fumigated wooden crates

Rubber end caps

Customer Cases

 GNEE specializes in exporting ASTM A312 TP321 titanium‑stabilized stainless steel pipes, including seamless and welded pipes complying with ASTM A312 standard.

No.	Export Country/Region	Order Date	Product Specifications & Standards	Application Scenarios
1	UAE	Feb 2026	ASTM A312 TP321 seamless pipes, Φ76×6 mm, solution‑annealed, pickled, titanium‑stabilized	High‑temperature heat exchanger piping for petrochemical projects, operating at 430‑650 °C, on‑site solution treatment unavailable after welding
2	Indonesia	Sep 2025	ASTM A312 TP321 welded pipes, Sch40S, TIG‑welded with integral solution annealing	High‑temperature steam transmission piping for biomass‑fired power plant boilers under alternating high‑temperature conditions
3	Kazakhstan	Apr 2025	ASTM A312 TP321 small‑diameter precision pickled pipes	Process piping for ammonia synthesis plants under high‑temperature, high‑pressure and corrosive conditions

 

1.Is SS 321 a better material than SS 304?

Type 321 and Type 304 stainless steel are both austenitic alloys, but 321 includes titanium stabilization, higher heat tolerance, and better resistance to weld decay compared to 304.

2.Is 321 stainless steel pipe magnetic or nonmagnetic?

No, 321 stainless steel is not magnetic when it is in its normal annealed condition. It belongs to the austenitic family of stainless steels, which have a face-centered cubic crystal structure that makes them non-magnetic

3.How to weld 321 stainless?

Welding 321 stainless steel pipe requires the use of 347 filler wire. For 18-gauge and 16-gauge piping, we recommend using TIG welding wire with a diameter of 0.030 to 0.035 inches.

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