Alloy 304 / 304L (UNS S30400 / S30403)
Alloy 304/304L is an austenitic stainless steel supplied in the hot worked and annealed condition. It offers good corrosion resistance in a wide range of atmospheric and mildly corrosive environments and is the most widely used stainless steel grade. The low carbon version, 304L, provides improved resistance to intergranular corrosion after welding.
The alloy exhibits excellent formability and weldability, with good toughness at both ambient and low temperatures. It is non-magnetic in the annealed condition and cannot be hardened by heat treatment. Alloy 304/304L is commonly used in food processing, chemical equipment, architectural applications, and general fabrication.
Specifications
- UNS: S30400 / S30403
- ASTM: A276, A182 F304/F304L, A240
- EN / DIN: 1.4301 (304) / 1.4307 (304L)
- Structure: Austenitic
- Condition Supplied: Annealed
Data Tables
Chemical Composition:
| C | Mn | P | S | Si | Cr | Ni | Ti | Mo | N | Cu | Fe | Co | Nb (+Ta) | V | W | Al | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 18 | 8 | |||||||||||||||
| Max | 0.08 | 2 | 0.045 | 0.03 | 1 | 20 | 10.5 | 0.1 | Bal |
Mechanical Properties:
| Material Grade | ASTM Standard | Desgnation(EN /UNS) | Yield Strength (MPa) | Yield Strength (KSI) | Tensile Strength (MPa) | Tensile Strength (KSI) | Elongation (%) | Reduction of Area (%) | Hardness(HRC/HBWMax) | Condition | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| SS 304 / 304L | ASTM A276 / A182 / A479 | EN 1.4301 / 1.4307(S30400/S30403) | 205 | 29.73279 | 515 | 74.69457 | 30 | 40 | 215 HBW-NACE | Solution Annealed |
Physical Properties:
| Material Grade | Density (g/cm³) | Melting Range (°C) | Modulus of Elasticity (GPa) | Thermal Conductivity (W/m·K) | Thermal Expansion (×10⁻⁶ /°C) | Electrical Resistivity (µΩ·m) | Magnetic Behavior |
|---|---|---|---|---|---|---|---|
| 304 / 304L | 7.9 | 1400–1450 | 193 | 14–16 | 17.3 | 0.72 | Non-magnetic |
Key Features
- Good general corrosion resistance
- Excellent formability and weldability
- Cost-effective and widely used stainless steel
- Non-magnetic in annealed condition
- 304L offers improved resistance to weld decay
Applications
- Food and beverage equipment
- Storage tanks and piping systems
- Architectural and decorative applications
- Kitchen and catering equipment
- General fabrication