ASTM A312/A312M (焊接) — Welded austenitic stainless steel pipe
Grades
TP304, TP304L, TP304H, TP309S, TP310S, TP316, TP316L, TP316H, TP317, TP317L, TP321, TP321H, TP347, TP347H
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 (welding) specifications are for welded austenitic stainless steel pipes used in high-temperature and general corrosive environments. These pipes are typically delivered after solution annealing following welding. The grades cover standard, ultra-low carbon, molybdenum-containing, and stabilized austenitic varieties, balancing corrosion resistance, high-temperature strength, and good weldability. They meet pressure transport requirements and are suitable for industrial piping systems operating from room temperature to higher temperatures and handling corrosive media.
Typical applications
Widely used in process pipelines in the chemical and petrochemical industries, fluid pipelines in the food processing and pharmaceutical industries, as well as water supply, drainage, and public works pipelines. Ultra-low carbon and molybdenum-containing varieties are suitable for post-weld corrosion resistance or highly corrosive conditions, while stabilized varieties are beneficial for resistance to intergranular corrosion. Also used in building decoration and structural pipes, it is often used as a medium-to-large diameter pressure and transport main pipe due to its economic efficiency and good weldability.
