- Description
308 stainless steel plate is not a commonly standardized base stainless steel grade like 304 or 316. In most industrial usage, “308 stainless steel” refers to a chromium-nickel austenitic alloy primarily used as a welding filler metal (308 / ER308 / 308L) that is closely related to 304 stainless steel chemistry.
In plate form, it is generally understood as a 304-compatible austenitic stainless steel with stabilized welding and corrosion performance, widely used in welded fabrication systems.
Chemical Composition of 308 Stainless Steel Plate
The composition is designed to provide strong weldability and corrosion resistance similar to 304 stainless steel, but with optimized welding performance.
| Element | Content (%) |
|---|---|
| Chromium (Cr) | 18.0–20.0 |
| Nickel (Ni) | 9.0–11.0 |
| Carbon (C) | ≤ 0.08 (or ≤ 0.03 for 308L) |
| Manganese (Mn) | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.03 |
| Iron (Fe) | Balance |
Mechanical Properties
308 stainless steel exhibits typical austenitic stainless steel performance with good strength and excellent ductility.
| Property | Typical Value |
|---|---|
| Tensile Strength | 520–750 MPa |
| Yield Strength | ≥ 205 MPa |
| Elongation | ≥ 40% |
| Hardness | ≤ 200 HB |
| Density | 7.9 g/cm³ |
Main Performance Features
1. Excellent Weldability
308 stainless steel is widely recognized for its excellent welding compatibility, especially for joining:
- 304 stainless steel
- Similar austenitic stainless steels
It is commonly used as a matching or over-alloyed filler material to improve weld strength and corrosion resistance.
2. Good Corrosion Resistance
It provides corrosion resistance similar to 304 stainless steel, suitable for:
- Atmospheric environments
- Mild chemical exposure
- Food-grade processing environments
- Water systems
It performs well in general industrial conditions but is not intended for highly chloride-rich environments.
3. Stable Austenitic Structure
308 stainless steel maintains a fully austenitic structure, offering:
- Non-magnetic behavior (annealed condition)
- Good toughness at low temperature
- Stable mechanical properties after welding
4. Good Formability
The material has excellent processing performance:
- Bending
- Stamping
- Rolling
- Deep drawing
- Fabrication of welded assemblies
Common Applications of 308 Stainless Steel Plate
308 stainless steel plate is mainly used in welding-related fabrication and general industrial structures.
Typical applications include:
- Welding fabrication structures
- Stainless steel pipe welding systems
- Pressure vessel welding components
- Food processing equipment
- Chemical equipment linings
- Heat exchanger assemblies
- Industrial storage tanks
- Structural welded frames
- Automotive exhaust welding parts
- General stainless steel fabrication projects
308 Stainless Steel vs 304 Stainless Steel
| Property | 308 Stainless Steel | 304 Stainless Steel |
|---|---|---|
| Main Role | Welding & fabrication support | Base structural material |
| Composition | Slightly higher Ni balance | Standard 18-8 stainless |
| Weldability | Excellent | Good |
| Corrosion Resistance | Similar | Good |
| Typical Use | Welding filler / welded systems | General fabrication |
