ASME SA350 LF2 Class 1 Forged Carbon Steel Nozzle Cover Flange for Piping Systems
ASME SA350 LF2 Class 1 Forged Carbon Steel Nozzle Cover Flange for Piping Systems
YUHONG GROUP specializes in manufacturing ASME-certified forged steel flanges for critical low-temperature applications. Our ASTM A350 LF2 Class 1 Forged Carbon Steel Nozzle Cover Flanges are engineered to deliver reliable performance in cryogenic piping systems operating as low as -46°C.
Chemical Composition of ASTM A350 LF2 (UNS K03011) Forged Steel Flange
| Element | Requirement (%) | Notes |
| Carbon (C) | ≤0.30 | Controlled for weldability |
| Manganese (Mn) | 0.60-1.35 | Enhances strength and toughness |
| Phosphorus (P) | ≤0.035 | Minimizes brittleness |
| Sulfur (S) | ≤0.040 | Improves machinability |
| Silicon (Si) | 0.15-0.30 | Deoxidizer and strength enhancer |
| Nickel (Ni) | ≤0.40 | Part of the alloy sum restriction |
| Chromium (Cr) | ≤0.30 | Part of the Cr+Mo sum restriction |
| Molybdenum (Mo) | ≤0.12 | Part of the Cr+Mo sum restriction |
| Copper (Cu) | ≤0.40 | Part of the alloy sum restriction |
| Columbium (Cb) | ≤0.02 | Controlled for weldability |
| Vanadium (V) | ≤0.08 | Grain refinement control |
Tensile Properties for ASTM A350 LF2 Class 1/2
| Property | Requirement for LF2 Class 1 & 2 | Notes |
| Tensile strength | 70-95 ksi [485-655 MPa] | Range applies to both Class 1 & 2 |
| Yield strength, min | 36 ksi [250 MPa] | By a 0.2% offset or a 0.5% extension method |
| Elongation (standard round specimen) | 22% min in 4D gauge length | For full-section testing |
| Elongation (strip specimen) | 30% min in 2 in. (50 mm) | For thickness ≥7.94 mm |
| Reduction of area, min | 30% | Applies to round specimens only |
Impact Test Temperature for ASME SA350
| Grade | Test Temperature, °F [°C] |
| LF1 | -20 [-29] |
| LF2, Class 1 | -50 [-46] |
| LF2, Class 2 | 0 [-18] |
| LF3, Classes 1 and 2 | -150 [-101] |
| LF5, Classes 1 and 2 | -75 [-59] |
| LF6, Classes 1 and 2 | -60 [-51] |
| LF6, Class 3 | 0 [-18] |
| LF9 | -100 [-73] |
| LF787, Class 2 | -75 [-59] |
| LF787, Class 3 | -100 [-73] |
Key Advantages of ASTM A350 LF2 Class 1 Forged Carbon Steel Nozzle Cover Flange
1. Certified Low-Temperature Performance
Guaranteed impact toughness at -46°C (-50°F) per ASTM A350 Table 4
Class 1 designation ensures superior performance in cryogenic service compared to Class 2
2. Optimized Material Composition
Controlled carbon content (≤0.30%) enables excellent weldability without preheat requirements
Manganese content (0.60-1.35%) provides an optimal balance of strength and toughness
3. Manufacturing Reliability
Forged construction eliminates defects and ensures structural integrity under pressure
Full traceability with heat number marking and EN 10204 3.1 certification available
4. Quality Verification
100% non-destructive testing (PT/MT/UT) available upon request
Third-party inspection acceptance (SGS/BV/DNV)
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