ASTM A249/A249M Type 316 Introduce
ASTM A249/A249M Type 316 is an austenitic stainless steel specifically designed for use in boiler, superheater and heat exchanger tubes, which contain higher amounts of chromium and nickel compared to other stainless steels. This grade of steel is popular for its ability to resist corrosion and oxidation, and for its high strength-to-weight ratio. Due to its outstanding properties, it is ideal for a range of applications, such as pressure vessels, heat exchangers, and condensers.
Smelting temperature:1537°C - 1578°C
Application:Welded austenitic steel tubes for boilers, superheaters, heat exchangers and condensers
ASTM A249/A249M Type 316 Material Chemical Composition
The chemical composition of the ASTM A249/A249M Type 316 steel are as follows:
| Element | Min | Max |
|---|---|---|
| Silicon (Si) | - | 1.0000 |
| Sulfur (S) | - | 0.0300 |
| PhOsphorus (P) | - | 0.0450 |
| Nickel (Ni) | 10.0000 | 14.0000 |
| Molybdenum (Mo) | 2.0000 | 3.0000 |
| Manganese (Mn) | - | 2.0000 |
| Chromium (Cr) | 16.0000 | 18.0000 |
| Carbon (C) | - | 0.0800 |
ASTM A249/A249M Type 316 Material Mechanical Properties
Yield strength is the point in which a material permanently deforms or bends without breaking. The yield strength of ASTM A249/A249M Type 316 steel ranges from 250 MPa to 450 MPa, depending on the grade of steel and the desired characteristics. The higher the yield strength, the higher the steel's resistance to deformation and breaking before reaching its permanent deformation point.
The mechanical properties of the ASTM A249/A249M Type 316 steel are as follows:
| YieldRp0.2 | ≤ 863 (MPa) |
| TeileRm | ≤ 123 (MPa) |
| ImpactKV/Ku | 43(J) |
| ElongationA | 24% |
| Reduction in cross section on fractureZ | 11% |
| As-Heat-Treated Condition | Solution and Aging, Annealing, Ausaging, Q+T,etc |
| Brinell hardness (HBW) | 334 |
ASTM A249/A249M Type 316 Material Thermal Properties
The thermal performance parameters of the ASTM A249/A249M Type 316 steel are as follows:
| Temperature (°C) | 32 | 197 | 221 |
| Modulus of elasticity (GPa) | - | 611 | - |
| Mean coefficient of thermal expaion ×10-6/(°C) | - | - | 23 |
| Thermal conductivity (W/m·°C) | - | 22.3 | 23.2 |
| Specific thermal capacity (J/kg·°C) | - | 424 | - |
| Specific electrical resistivity (Ω mm²/m) | 0.21 | - | - |
| Deity (kg/dm³) | - | - | 342 |
| Poisson’s coefficient, ν | - | - | 333 |
ASTM A249/A249M Type 316 Material Machining Technology
There are several methods for machining ASTM A249/A249M Type 316 steel. It can be machined using traditional methods such as drilling, tapping, reaming, milling, and turning. It can also be machined using specialized techniques such as electrochemical machining and laser machining. When it comes to high-precision machining, electrochemical machining is the preferred method as it is capable of producing intricate components with extremely tight tolerances. With laser machining, components can be produced with increased accuracy and reduced lead time.