Introduction
ASTM A350 is a standard specification covering carbon steel and low-alloy steel forgings intended for low-temperature service. These materials are commonly used in the manufacture of flanges, valves, fittings, and other pressure-containing parts where notch toughness and impact resistance at low temperatures are required.
ASTM A350 is widely applied in industries such as oil & gas, petrochemical, LNG, power generation, and offshore engineering, especially in cold climate or cryogenic service conditions.
Scope of ASTM A350
ASTM A350 specifies requirements for:
- Chemical composition
- Mechanical properties
- Impact testing (Charpy V-notch)
- Heat treatment
- Testing, inspection, and certification
Grades of ASTM A350
ASTM A350 includes several grades designed for different temperature ranges and service conditions.
ASTM A350 LF2 (Most Common)
- Carbon steel forging with impact testing
- Widely used for low-temperature flanges and fittings
ASTM A350 LF3
- Nickel alloy steel
- Enhanced low-temperature toughness
Chemical Composition (Typical – ASTM A350 LF2)
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.30 |
| Manganese (Mn) | 0.60 – 1.35 |
| Silicon (Si) | 0.15 – 0.35 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.040 |
| Nickel (Ni) | ≤ 0.40 |
Mechanical Properties (Typical – ASTM A350 LF2)
| Property | Requirement |
|---|---|
| Tensile Strength | 485 – 620 MPa |
| Yield Strength | ≥ 250 MPa |
| Elongation | ≥ 20% |
| Impact Test | Required at specified temperature |
Heat Treatment
ASTM A350 forgings are typically supplied in one of the following conditions:
- Normalized
- Normalized and tempered
- Quenched and tempered (when specified)
The heat treatment must ensure compliance with both mechanical and impact requirements.
Applications
ASTM A350 materials are widely used for:
- Low-temperature flanges
- Valves and valve bodies
- Pressure vessels
- LNG and cryogenic piping systems
- Offshore and cold-region pipelines
Product Forms
- Forged flanges (Weld neck flanges,Blind Flange,Slip on flange,socket weld flanges)
- Forged valve components
- Forged fittings
- Custom machined forgings
Download ASTM A350 Standard (Reference)
📄 Download ASTM A350 Standard Specification PDF
Inquiry
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