X2CrNi18-9
The low-carbon version of 304. Safe against intergranular corrosion after welding (sensitization); replaces 304 in welded bodies and piping.
- Rp0.2 · MPa
- ≥ 200
- Rm · MPa
- 500–700
- TEMPERATURE
- −196 … +425 °C
- COST
Chemical composition
Mechanical properties
| STANDARD · CONDITION | Rp0.2 MPa | Rp1.0 MPa | Rm MPa | A % | KV J |
|---|---|---|---|---|---|
| EN 10088-2 · hot-rolled plate (P) | 200 | 240 | 500–700 | 45 | 60 |
| EN 10028-7 · −196 °C | 300 | 400 | ≥ 1200 | 30 | — |
| ASTM A240 · 304L | 170 | — | ≥ 485 | 40 | — |
Room temperature, solution annealed. KV ≥ 60 J (+20 °C and −196 °C, transverse).
Minimum Rp0.2 at elevated temperature
| EN · TEMPERATURE | 20 °C | 100 °C | 200 °C | 400 °C |
|---|---|---|---|---|
| Rp0.2 MPa | 200 | 147 | 118 | 89 |
EN 10028-7 / EN 10088 values; the minimum proof strength used in pressure equipment design.
ASME B16.34 pressure-temperature ratings
| CLASS · bar | −29 … 38 °C | 100 °C | 200 °C | 300 °C | 400 °C | 500 °C |
|---|---|---|---|---|---|---|
| Class 150 | 15.9 | 13.3 | 11.2 | 10.0 | 6.5 | — |
| Class 300 | 41.4 | 34.8 | 29.2 | 26.1 | 24.3 | — |
| Class 600 | 82.7 | 69.6 | 58.3 | 52.1 | 48.6 | — |
| Class 900 | 124.1 | 104.4 | 87.5 | 78.2 | 72.9 | — |
| Class 1500 | 206.8 | 173.9 | 145.8 | 130.3 | 121.5 | — |
| Class 2500 | 344.7 | 289.9 | 243.0 | 217.2 | 202.5 | — |
Standard class, bar. Material group: F304L/F316L. Greyed values are outside the material's service range (−196 … +425 °C). Flanged-end ratings end at 538 °C.
Service temperature
Not used below −196 °C (EN). Upper limit 425 °C.
This is the limit of the material itself. A valve's service temperature is usually set by the seal and seat materials; product pages give it for each seal option.
Physical properties and heat treatment
- DENSITY
- 7.9 kg/dm³
- MODULUS OF ELASTICITY (20 °C)
- 200 GPa
- THERMAL EXPANSION (20–100 °C)
- 16.0 × 10⁻⁶ /K
- THERMAL CONDUCTIVITY (20 °C)
- 15 W/m·K
- SPECIFIC HEAT (20 °C)
- 500 J/kg·K
- ELECTRICAL RESISTIVITY
- 0.73 µΩ·m
- MAGNETISM
- non-magnetic (solution annealed)
- CRITICAL PITTING TEMPERATURE, CPT (TYPICAL)
- < 10 °C
- HEAT TREATMENT
- Solution annealing 1050 ± 50 °C, rapid cooling.
Media suitability GENERAL TREND
Emsal assessment. The final choice is made from corrosion tables, taking concentration, temperature, chloride content and flow velocity into account.
Strengths and weaknesses
Strengths
- Resistant to intergranular corrosion after welding without heat treatment
- Cryogenic toughness
- Readily available as dual-certified (304/304L) plate
Weaknesses
- Lower proof strength than 304
- Chloride resistance the same as 304, limited
- Strength drops at elevated temperature
Manufacturing and use
- ECONOMY
- Low to medium; almost the same price as 304.
- MANUFACTURING METHODS
- Welded body from plate · Pipe and elbow · Machining
- TYPICAL VALVE PARTS
- Welded body · Pipe fittings · Flange
Source: EN 10088-2 / -3. Values compiled and verified by Emsal Vana; for binding values, refer to the current edition of the standard and the material certificate.