ASTM A511 MT 309S Stainless Steel Mechanical Tubing
ASTM A511 MT 309S Stainless Steel Mechanical Tubing - High-Temperature Austenitic Grade
Explore the chemical, mechanical and physical properties of ASTM A511 MT 309S seamless stainless steel mechanical tubing, a low-carbon austenitic grade with excellent oxidation resistance up to 1000 °C.
Hot finished, cold finished, annealed, pickled, bright annealed, cold drawn, temper rolling, cutting, bending, welding, forming
- Phone : +8618037372205
- Email : [email protected]
- WhatsApp: Contact via Whtsapp
- WeChat: +8618037372205
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Introduction
ASTM A511 MT 309S is a seamless austenitic stainless steel mechanical tubing grade with low carbon content (max 0.08%). It offers a combination of high chromium (22–24%) and nickel (12–15%) for superior oxidation resistance and high-temperature strength. This alloy maintains good mechanical properties in the annealed condition and is widely used in applications requiring resistance to heat and corrosion, such as furnace components, heat exchangers, and chemical processing equipment. Typical delivery condition is annealed and pickled, or bright annealed, with optional cold-worked tempers for higher strength.
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Chemical Composition
The chemical composition limits for ASTM A511 grade MT 309S seamless stainless steel mechanical tubing, as specified in ASTM A511. Note: Single values are maximums unless a range is given. The chromium and nickel levels provide the characteristic heat and oxidation resistance.
| Element | Standard Value (wt. %) | Remarks |
|---|---|---|
| Carbon (C) | ≤0.08 | Low carbon for improved intergranular corrosion resistance |
| Manganese (Mn) | ≤2.00 | Austenite stabilizer |
| Phosphorus (P) | ≤0.045 | Maximum allowable |
| Sulfur (S) | ≤0.030 | Maximum allowable |
| Silicon (Si) | ≤1.00 | Deoxidizer, improves oxidation resistance |
| Chromium (Cr) | 22.0–24.0 | Key element for oxidation and corrosion resistance |
| Nickel (Ni) | 12.0–15.0 | Stabilizes austenite, enhances ductility and high-temperature strength |
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Thermal and Electrical Physical Properties
Typical physical properties of 309S stainless steel at room temperature unless otherwise noted. These values are representative of the alloy in the annealed condition and are useful for design calculations. Note: Thermal expansion, conductivity, and specific heat vary with temperature; values provided are for indicative purposes.
| Property | Typical Value | Unit | Test Condition / Temperature |
|---|---|---|---|
| Density (ρ) | 8.0 | g/cm³ | 20 °C |
| Elastic Modulus (E) | 200 | GPa | 20 °C |
| Shear Modulus (G) | 77 | GPa | Calculated from E and ν |
| Poisson's Ratio (ν) | 0.30 | — | 20 °C |
| Thermal Expansion Coefficient (α) | 14.9 | µm/m·°C | 20–100 °C |
| Thermal Conductivity (λ) | 15.6 | W/m·K | 100 °C |
| Specific Heat Capacity | 500 | J/kg·K | 20 °C |
| Electrical Resistivity (ρ_e) | 0.78 | µΩ·m | 20 °C |
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Mechanical Properties
Minimum tensile properties for ASTM A511 MT 309S tubing in the annealed condition at room temperature. Test condition: Samples prepared from finished tubing and tested in accordance with ASTM A370. Values apply to wall thickness ≥ 5/16 in (7.94 mm); for thinner walls, reduced elongation requirements may apply.
| Property | Standard Requirement | Unit | Test Condition |
|---|---|---|---|
| Tensile Strength (Rm) | ≥515 (≥75) | MPa (ksi) | Annealed, room temperature |
| Yield Strength (ReH), 0.2% offset | ≥205 (≥30) | MPa (ksi) | Annealed, room temperature |
| Elongation (A) in 2 in. or 50 mm | ≥30 (for wall ≥5/16 in.) | % | Annealed, gauge length 2 in. (50 mm) |
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Fully Equivalent Material Standards & Substitute Grades
| Country / Region | Standard | Grade | Remarks |
|---|---|---|---|
| USA | ASTM A213 / A213M | TP 309S | Seamless ferritic/austenitic boiler tube, identical chemistry |
| USA | ASTM A269 | TP 309S | Seamless and welded austenitic stainless steel tubing for general service |
| USA | ASTM A312 / A312M | TP 309S | Seamless and welded austenitic stainless steel pipe |
| Japan | JIS G4304 | SUS 309S | Hot-rolled stainless steel plate, sheet and strip; equivalent low-carbon grade |
| China | GB/T 14976 | 06Cr23Ni13 | Seamless stainless steel pipes for fluid transport; matches 309S chemistry |
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Application Introduction
ASTM A511 MT 309S tubing is primarily employed in high-temperature environments where oxidation resistance is critical. Its balanced composition enables long service life in cyclic heating conditions. Typical uses span thermal processing, petrochemical, and power generation industries. The alloy can be fabricated into complex shapes and is readily weldable with matching filler metals.
Product Applications: Industrial furnace radiant tubes, muffles, and retorts, Annealing boxes and baskets, Heat exchanger tubes and tube sheets, Boiler boundary tubing and superheater elements, Kiln rollers and supports, High-temperature piping and manifolds, Thermocouple protection tubes
Processed into products: Radiant tube assemblies, Furnace rolls, Burner nozzles, Quench fixtures, Flue gas ducting liners, Steam reformer tubes, Catalyst support grids, Expansion joints
Application industries: Heat treatment & thermal processing (industrial furnaces), Petrochemical refineries & chemical plants, Power generation (boilers, superheaters), Cement, steel, and glass manufacturing (kilns, annealing lines), Automotive exhaust systems (high-temperature components), Food processing (high-temperature cooking equipment)
ASTM A511 MT 309S Stainless Steel Mechanical Tubing Similar / Near-Equivalent Material Recommendations
| Country / Region | Standard | Grade | Remarks |
|---|---|---|---|
| USA | ASTM A511 | MT 309 | Higher carbon (max 0.20%); slightly higher strength, lower intergranular corrosion resistance |
| USA | ASTM A511 | MT 310S | Higher chromium (24–26%) and nickel (19–22%); superior oxidation resistance for higher temperatures |
| Europe | EN 10095 | 1.4833 (X12CrNi23-13) | Carbon max 0.15%; commonly used as heat-resisting alternative; not low carbon |
| Japan | JIS G4304 | SUS 309 | Standard 309 with max 0.20% carbon; may be substituted where low carbon not critical |
Notes:
- The low carbon content minimizes carbide precipitation during welding, eliminating the need for post-weld annealing in many applications.
- 309S exhibits good resistance to scaling up to approximately 980–1000 °C in continuous service and can withstand intermittent exposure to 870 °C.
- For optimum corrosion resistance in the as-welded condition, the use of low-carbon or stabilized fillers is recommended.
- Material is typically supplied in lengths of up to 12 m; custom finishes (e.g., electropolished) are available on request.
- Share
