Alloy Steel Boiler and Superheater Tube ASME SA209 T1 T1a T1b Seamless
ASME SA209 is a specification under the ASME (American Society of Mechanical Engineers) standards for seamless carbon-molybdenum alloy-steel tubes used for boilers, superheaters, and heat exchangers. Within this specification, there are different grades, including T1, T1a, and T1b. Here's an overview of each:
1. ASME SA209 Grade T1:
- Chemical Composition:
- Carbon (C): 0.15% max
- Manganese (Mn): 0.30–0.80%
- Phosphorus (P): 0.025% max
- Sulfur (S): 0.025% max
- Molybdenum (Mo): 0.44–0.65%
- Typical Applications:
- Used in high-temperature applications such as boilers, superheaters, and heat exchangers.
2. ASME SA209 Grade T1a:
- Chemical Composition:
- Carbon (C): 0.05–0.15%
- Manganese (Mn): 0.30–0.80%
- Phosphorus (P): 0.025% max
- Sulfur (S): 0.025% max
- Molybdenum (Mo): 0.44–0.65%
- Differences from T1:
- T1a has a narrower range of carbon content compared to T1, allowing for slight variation in mechanical properties.
3. ASME SA209 Grade T1b:
- Chemical Composition:
- Carbon (C): 0.05–0.15%
- Manganese (Mn): 0.30–0.80%
- Phosphorus (P): 0.025% max
- Sulfur (S): 0.025% max
- Molybdenum (Mo): 0.44–0.65%
- Differences from T1 and T1a:
- Similar chemical composition to T1a, but the material may have different mechanical properties or intended applications.
General Characteristics:
- Mechanical Properties:
- Tensile strength, yield strength, and elongation are specified depending on the grade and the intended application.
- Heat Treatment:
- Tubes are typically furnished in a normalized or hot-finished condition.
- Applications:
- All grades are suited for environments where resistance to high temperature and pressure is essential.
ASTM A209 Chemical Composition:
| Grade | Carbon | Manganese | Phosphorus | Sulfur | Silicon | Molybdenum |
| Gr.T1 | 0.10% - 0.20% | 0.30% - 0.80% | 0.025% Max | 0.025% Max | 0.10% - .050% | 0.44% - .065% |
| Gr.T1a | 0.15% - 0.25% | 0.30% - 0.80% | 0.025% Max | 0.025% Max | 0.10% - 0.50% | 0.44% - .065% |
| Gr.T1b | 0.14% Max | 0.30% - 0.80% | 0.025% Max | 0.025% Max | 0.10% - 0.50% | 0.44% - .065% |
ASTM A209 Mechanical Properties:
| Grade | Tensile Strength (Mpa) | Yield Strength (Mpa) | Elongation(%) | Hardness(HRB) |
| Gr.T1 | ≥380 | ≥205 | ≥30 | ≤80 |
| Gr.T1a | ≥365 | ≥195 | ≥30 | ≤81 |
| Gr.T1b | ≥415 | ≥220 | ≥30 | ≤77 |
