p355gh vs s355j2
Chemical Composition
| Element | P355GH (Pressure Vessel Steel) | S355J2 (Structural Steel) | Key Differences |
|---|---|---|---|
| Carbon (C) | ≤ 0.18% | ≤ 0.22% | P355GH has a lower max carbon content for improved weldability and toughness in pressure systems; S355J2 allows slightly higher carbon for general structural strength. |
| Silicon (Si) | ≤ 0.60% | Usually ≤ 0.50% (not always specified) | P355GH allows higher silicon for enhanced deoxidation and high-temperature scaling resistance; S355J2 focuses on structural ductility. |
| Manganese (Mn) | 1.10–1.70% | 1.00–1.65% | Similar ranges, but P355GH tends toward the higher end for pressure integrity; S355J2 is optimized for structural fabrication. |
| Phosphorus (P) | ≤ 0.025% | ≤ 0.025% (for S355J2 grade) | Both have strict phosphorus limits for toughness, but P355GH may enforce this more rigorously for pressure safety. |
| Sulfur (S) | ≤ 0.010% | ≤ 0.035% (common for S355J2) | P355GH has much stricter sulfur control to prevent hot cracking under pressure; S355J2 allows higher sulfur for easier machining in non-critical structures. |
| Alloying Elements | May contain trace Mo, Nb, V for high-temp strength | Usually plain carbon-manganese; may have microalloying (Nb, V, Ti) for strength | P355GH uses alloying for pressure and high-temperature performance; S355J2 uses microalloying for structural strength and weldability. |
Mechanical Properties
| Property | P355GH (EN 10028-2) | S355J2 (EN 10025-2) | Key Differences |
|---|---|---|---|
| Yield Strength (ReH) | ≥ 355 MPa (thickness ≤ 16mm) | ≥ 355 MPa (thickness ≤ 16mm) | Similar yield strength, but P355GH is tested under pressure-specific conditions; S355J2 is for general structural loading. |
| Tensile Strength (Rm) | 490–630 MPa | 470–630 MPa | Overlapping ranges, but P355GH tends to have a higher minimum tensile strength for pressure containment. |
| Elongation (A5) | ≥ 20% (thickness ≤ 16mm) | ≥ 22% (longitudinal, thickness ≤ 16mm) | S355J2 requires slightly better elongation for structural ductility; P355GH prioritizes strength for pressure vessels. |
| Impact Toughness | ≥ 27 J at 0°C (mandatory for pressure safety) | ≥ 27 J at -20°C (J2 grade requirement) | S355J2 has a lower impact test temperature (-20°C vs. 0°C for P355GH), making it suitable for colder structural environments; P355GH focuses on room-temperature toughness for pressure systems. |
Key Application-Related Properties
| Property/Application | P355GH | S355J2 | Key Differences |
|---|---|---|---|
| Heat Treatment | Usually normalized (N) or quenched & tempered | Usually supplied in hot-rolled or normalized condition | P355GH often requires normalization for pressure integrity; S355J2 is typically hot-rolled for cost-effectiveness. |
| Intended Use | High-pressure vessels, boilers, and high-temp piping systems | General structural applications (buildings, bridges, machinery frames) | P355GH is for pressure-containing equipment; S355J2 is for load-bearing structures in various environments. |
| Weldability | Good, but requires careful procedures for pressure systems | Excellent, with simple welding techniques | S355J2 is easier and more economical to weld; P355GH needs controlled welding to maintain pressure integrity. |
| High-Temperature Performance | Suitable for temperatures up to ~400°C (retains strength well) | Not designed for high-temperature service; may degrade above 300°C | P355GH is optimized for moderate elevated temperatures; S355J2 is for ambient or low-temperature structural use. |
| Cold-Temperature Performance | Limited (impact tested at 0°C) | Excellent (impact tested at -20°C) | S355J2 is better suited for cold climates; P355GH is not intended for low-temperature pressure service. |
| Standard Reference | EN 10028-2 (pressure vessel steel) | EN 10025-2 (structural steel) | Different standards with distinct requirements based on application. |
P355GH boiler tube factory
