ASTM A694 F70 Carbon Steel Flange
ASTM A694 F70 Specification:
- Grade: A694 F42 Carbon Steel
- Standard: ASTM A694 / ASME SA694
- Type: Carbon Steel
- Form: Flanges (Slip-on Flange, Weld Neck Flange, Blind Flange, Socket Weld Flange, Threaded Flange, Lap Joint Flange, Plate Flange)
- Size: Available in various dimensions (½”, ¾”, 1”, 1 ¼”, 1 ½”, 2”, 2 ½”, 3”, 4”, 5”, 6”, 8”, 10”, 12”, 14”, 16”, 18”, 20”, 24”, 26”, 28”, 30”, 32”, 34”, 36”, 38”, 40”, 42”, 44”, 46”, 48”)
- Pressure Class: 150, 300, 600, 900, 1500, 2500
- End Types: Flanged, Threaded, Welded
Common Flange Types in ASTM A694 F70:
- Weld Neck Flange (WNRF)
- Slip-On Flange (SORF)
- Blind Flange (BLRF)
- Socket Weld Flange (SWRF)
- Threaded Flange
- Lap Joint Flange
A694 F42 Material Properties:
ASTM A694 F70 is a carbon steel forging material designed for high-pressure applications. It exhibits good mechanical strength and moderate corrosion resistance.
A694 F42 Chemical Composition:
| Element | Composition (%) |
|---|---|
| Carbon (C) | ≤ 0.26 |
| Manganese (Mn) | 1.35 – 1.65 |
| Phosphorus (P) | ≤ 0.025 |
| Sulfur (S) | ≤ 0.025 |
| Silicon (Si) | 0.15 – 0.35 |
| Nickel (Ni) | ≤ 0.50 |
| Chromium (Cr) | ≤ 0.30 |
| Molybdenum (Mo) | ≤ 0.12 |
| Vanadium (V) | ≤ 0.08 |
A694 F42 Mechanical Properties:
| Property | Value |
|---|---|
| Tensile Strength (MPa) | ≥ 415 |
| Yield Strength (MPa) | ≥ 290 |
| Elongation (%) | ≥ 22 |
| Hardness (HB) | ≤ 197 |
A694 F42 Physical Properties:
| Property | Value |
|---|---|
| Density | 7.85 g/cm³ |
| Melting Point | 1420 – 1460°C |
| Thermal Conductivity | 45 W/m.K |
| Electrical Resistivity | 0.1 Ω·m |
Possible Alternative Grades:
| Standard | Equivalent Grades |
|---|---|
| ASTM A105 | Carbon Steel Forgings |
| ASTM A350 LF2 | Low-Temperature Carbon Steel |
| ASTM A182 F52 | Stainless Steel |
| ASTM A516 Gr. 60 | Pressure Vessel Steel |
Chemical Formula:
ASTM A694 F70 is mainly composed of iron (Fe), carbon (C), manganese (Mn), phosphorus (P), sulfur (S), and silicon (Si), providing a balanced combination of strength and weldability.
Grade Specification Comparison:
| Property | ASTM A694 F70 | ASTM A105 | ASTM A350 LF2 |
|---|---|---|---|
| Tensile Strength (MPa) | ≥ 415 | ≥ 485 | ≥ 485 |
| Yield Strength (MPa) | ≥ 290 | ≥ 250 | ≥ 260 |
| Hardness (HB) | ≤ 197 | ≤ 187 | ≤ 197 |
Corrosion Resistance:
ASTM A694 F70 has moderate corrosion resistance, making it suitable for mildly corrosive environments. However, it may require protective coatings or linings for use in highly corrosive conditions.
Heat Resistance:
This grade maintains its mechanical integrity at elevated temperatures up to 600°C but is not recommended for prolonged exposure to extreme heat without proper heat treatment.
Heat Treatment:
ASTM A694 F70 flanges undergo normalizing, quenching, and tempering to enhance mechanical properties. The standard heat treatment cycle includes:
- Normalizing Temperature: 890 – 950°C
- Quenching Medium: Water or oil
- Tempering Temperature: 540 – 680°C
Welding:
- Readily weldable using conventional welding techniques.
- Preheating may be required for thick sections.
- Post-weld heat treatment (PWHT) is recommended for high-stress applications.
- Suitable for MIG, TIG, SMAW, and FCAW welding processes.
Fabrication:
- It can be machined using conventional techniques.
- Requires carbide or high-speed steel tools for better machinability.
- Cold and hot forming is possible but requires preheating before forging.
Applications:
ASTM A694 F70 flanges are widely used in high-pressure and high-temperature applications, including:
- Oil & Gas Pipelines – Suitable for transporting crude oil, natural gas, and petrochemicals.
- Petrochemical Plants – Used in process piping and pressure vessels.
- Power Generation – Ideal for thermal, nuclear, and hydroelectric power plants.
- Shipbuilding & Marine – Utilized in offshore drilling platforms and ship piping systems.
- Construction & Infrastructure – Used in structural applications requiring high strength.