ASTM A312 TP321H Stainless Steel Seamless Pipe

What is ASTM A312 TP321H?

ASTM A312 TP321H is the high-carbon variant of TP321, optimized for high-temperature creep strength, used in high-stress, high-temp piping systems (boilers, superheaters).

Equivalent Grades (Horizontal)UNS: S32109 | JIS: SUS321H | GB: 07Cr18Ni11Ti | EN: X7CrNiTi18-10 | W.Nr.: 1.4541

Chemical Composition (wt%, Horizontal)C: 0.04-0.10 | Si: ≤1.00 | Mn: ≤2.00 | P: ≤0.045 | S: ≤0.030 | Cr: 17.00-19.00 | Ni: 9.00-12.00 | Ti: ≥5×C | Fe: Balance

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

Key Properties (20°C, Annealed, Horizontal)Density: 7.93g/cm³ | Melting Point: 1400-1450°C | Tensile Strength: ≥515N/mm² | Yield Strength: ≥205N/mm² | Elongation: ≥40% | Hardness: ≤201HB

Core Characteristics

Superior high-temperature creep strength (600-870°C)

Excellent post-weld corrosion resistance

Mandatory post-weld annealing for full performance

For high-temp, high-stress pressure piping

TP321 vs TP321H (Horizontal)Carbon: 321 (≤0.08%) | 321H (0.04-0.10%) | Creep Strength: 321 (Good) | 321H (Excellent) | Annealing: 321 (Optional) | 321H (Mandatory)

 

Stainless Steel Suppliers

If you have project requirements for stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
Packaging: Wooden crate packaging, bubble wrap packaging, steel strapping, or packaging according to customer requirements.