ASTM A312/A312M — Seamless and welded austenitic stainless steel pipes
Grades
TP304, TP304L, TP304H, TP309S, TP309H, TP310S, TP310H, TP316, TP316L, TP316H, TP317, TP317L, TP321, TP321H, TP347, TP347H, TP348, TP348H
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| TP304 | C≤0.08, Si≤0.75, Mn≤2.00, P≤0.045, S≤0.030, N≤0.10, Cr 18.00-20.00, Ni 8.00-11.00 | Rm ≥515 MPa, Rp0.2 ≥205 MPa, A≥40%, HB≤201, austenitic 304 |
| TP304L | C≤0.030, Si≤0.75, Mn≤2.00, P≤0.045, S≤0.030, N≤0.10, Cr 18.00-20.00, Ni 8.00-12.00 | Rm ≥485 MPa, Rp0.2 ≥170 MPa, A≥40%, HB≤201, austenitic ultra-low carbon 304L |
| TP304H | C 0.04-0.10, Si≤0.75, Mn≤2.00, P≤0.045, S≤0.030, Cr 18.00-20.00, Ni 8.00-11.00 | Rm ≥515 MPa, Rp0.2 ≥205 MPa, A≥40%, HB≤201, austenitic high temperature 304H |
Application scope
ASTM A312/A312M specifications define seamless and weldable austenitic stainless steel pipes for use in high-temperature and generally corrosive environments. They are typically delivered in a solution-annealed condition. The grades cover standard, ultra-low carbon, molybdenum-containing, and stabilized austenitic varieties, offering excellent corrosion resistance, high-temperature strength, and weldability. They meet pressure transport requirements and are suitable for industrial piping systems operating at temperatures ranging from room temperature to higher temperatures and for media with a degree of corrosivity.
Typical applications
Widely used in high-temperature process pipelines in chemical and petrochemical industries, oil refining unit pipelines, and public works pipelines, as well as for media transportation in papermaking, food processing, and seawater treatment equipment. Molybdenum-containing and ultra-low carbon varieties are suitable for highly corrosive conditions or applications requiring resistance to intergranular corrosion, and are often used as pressure main pipes, branch pipes, and header connection pipes, serving fluid transportation systems that require both corrosion resistance and temperature resistance.
