X2CrNiMoCuWN25-7-4
Super duplex alloyed with copper and tungsten. In the same strength class as 2507; widely used in seawater and oil and gas systems.
- Rp0.2 · MPa
- ≥ 530
- Rm · MPa
- 730–930
- TEMPERATURE
- −40 … +300 °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) | 530 | — | 730–930 | 25 | 90 (+20 °C) · 40 (−40 °C) |
| ASTM · S32760 | 550 | — | ≥ 750 | 25 | — |
Room temperature, solution annealed. KV ≥ 90 J (+20 °C), ≥ 40 J (−40 °C), transverse.
Minimum Rp0.2 at elevated temperature
| EN · TEMPERATURE | 20 °C | 100 °C | 200 °C |
|---|---|---|---|
| Rp0.2 MPa | 530 | 450 | 400 |
EN 10028-7 / EN 10088 values; the minimum proof strength used in pressure equipment design.
Service temperature
Lower value: the lowest temperature for which EN gives an impact requirement (−40 °C, KV ≥ 40 J). Upper limit ~300 °C (475 °C embrittlement).
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
- 7.8 kg/dm³
- MODULUS OF ELASTICITY (20 °C)
- 200 GPa
- THERMAL EXPANSION (20–100 °C)
- 13.0 × 10⁻⁶ /K
- THERMAL CONDUCTIVITY (20 °C)
- 15 W/m·K
- SPECIFIC HEAT (20 °C)
- 500 J/kg·K
- ELECTRICAL RESISTIVITY
- 0.80 µΩ·m
- MAGNETISM
- magnetic
- CRITICAL PITTING TEMPERATURE, CPT (TYPICAL)
- 84 ± 2 °C
- HEAT TREATMENT
- Solution annealing 1080 ± 40 °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
- Super duplex-class seawater resistance
- Copper addition: better than 2507 in sulphuric acid
- High strength
Weaknesses
- Risk of sigma phase, strict production control
- Expensive and limited stock
- Not used above ~300 °C
Manufacturing and use
- ECONOMY
- High; similar to 2507.
- MANUFACTURING METHODS
- Machining from bar and forging
- TYPICAL VALVE PARTS
- Body · Stem · Disc
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.