ASTM A269/A269M — Seamless and welded austenitic stainless steel pipes are generally used.
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 A269/A269M specifies seamless and weldable austenitic stainless steel tubing for general corrosion resistance and general purpose applications. Delivery is typically in the solution-annealed and pickled condition. The listed austenitic grades offer good corrosion resistance, formability, and weldability. Molybdenum-containing and ultra-low carbon grades enhance resistance to pitting and intergranular corrosion. The standard focuses on general-purpose conveying tubing for ambient to intermediate temperature applications, suitable for cleanliness and corrosion resistance requirements.
Typical applications
Widely used in process piping and instrumentation in the chemical and petrochemical industries, as well as for sanitary fluid transportation in the food, beverage, dairy, and pharmaceutical industries. Also used for water supply and drainage, pure water, and general corrosion-resistant media pipelines; molybdenum-containing varieties are suitable for environments with slightly stronger corrosion. Due to its good corrosion resistance and weldability, it is commonly used as instrument pressure taps, small-diameter coils, heat exchange coils, and general-purpose corrosion-resistant connecting pipes.
