ASTM A358/A358M — High-temperature electrofusion welded austenitic chromium-nickel stainless steel pipe
Grades
TP304, TP304L, TP304H, TP316, TP316L, TP316H, TP321, TP321H, TP347, TP347H, TP309S, TP310S
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 A358/A358M specifies electrofusion welded austenitic chromium-nickel stainless steel pipes for high-temperature applications. These pipes are typically delivered after solution heat treatment and according to different weld inspection grades. This standard is suitable for larger diameter, thicker-walled welded pipes. The grades are primarily conventional, molybdenum-containing, and stabilized austenitic, offering high-temperature strength, oxidation resistance, and corrosion resistance. They are suitable for large-diameter pipes subjected to pressure and long-term exposure to high-temperature corrosive environments.
Typical applications
Widely used in high-temperature process pipelines, oil transfer lines and gas collection pipes of heating furnaces in chemical and oil refining plants, as well as high-temperature heat exchanger shells and large-diameter conveying pipes. Large-diameter thick-walled pipes can be manufactured using electrofusion welding technology. Molybdenum-containing and stabilized varieties are suitable for resistance to intergranular corrosion and high-temperature continuous operation, and are commonly used in pressure-bearing main pipelines with high wall temperatures and corrosive media in the petrochemical and energy sectors.
