The operating temperature range of P355GH welded pipe can be divided into long-term service temperature and short-term peak temperature according to working conditions, as follows:
1. Core temperature range
| Temperature Type | Temperature range | Key performance requirements |
|---|---|---|
| Long-term service temperature | -10℃ ~ +400℃ | Maintain stable mechanical properties and creep resistance |
| Short-term peak temperature | ≤540℃ | Allowing short-term over-temperature operation (such as accident conditions) |
2. Temperature-related performance characteristics
High temperature strength retention rate:
300℃: Yield strength ≥285 MPa (retain more than 80% of room temperature strength);
350℃: 10⁵-hour endurance strength ≥110 MPa (critical value for creep resistance).
Low temperature toughness guarantee:
-20℃ impact energy: ≥27 J (to ensure the ability to resist brittle fracture in low temperature environment).
️
3. Temperature limit precautions
Low temperature lower limit:
When the design temperature is lower than -10℃, additional evaluation of low temperature impact toughness is required;
High temperature upper limit:
When used for a long time at ＞400℃, the stress level must be controlled to ≤80% of the high temperature yield strength;
When the material oxidation rate increases significantly at ＞450℃ (anti-corrosion coating is required)
4. Typical application scenario temperature
| Applications | Operating temperature | Case |
|---|---|---|
| Power station main steam pipeline | 300–400℃ | Supercritical unit 540℃ short-term overload |
| Chemical reactor heat exchange tubes | 200–350℃ | Long-term operation in sulfur-containing medium environment |
| Boiler drum | 280–400℃ | 100,000 hours lifespan at 17.5MPa pressure |
