S355J0 and S355J2 are high-strength structural steels under EN 10025-2, with the main difference being their specified impact toughness test temperature: S355J0 requires 27 Joules at 0°C, while S355J2 requires the same 27 Joules at a much colder -20°C, making S355J2 better for cold environments, though both share similar yield strength (355 MPa) and chemical compositions.
Key Differences:
Impact Testing Temperature:
S355J0:
Impact Test Temperature: 0°C (32°F).
Notch Toughness: The steel is tested for its impact energy at 0°C. This means it is designed to maintain toughness at this temperature without becoming brittle.
S355J2:
Impact Test Temperature: -20°C (-4°F).
Notch Toughness: The steel is tested for impact energy at -20°C. This makes S355J2 suitable for colder environments where materials need to retain toughness at lower temperatures.
Application Suitability:
S355J0:
Suitable for general structural applications where temperatures are around 0°C or higher.
S355J2:
More suitable for colder climates or applications where temperatures may drop to -20°C or lower, such as outdoor structures, bridges, or infrastructure in cold environments.
chemical composition:
| Grade | C | Si | Mn | P | S | Cu | N |
| S355J2 | 0.24 max | 0.60 max | 1.70 max | 0.035 max | 0.035 max | 0.60 max | 0.014 max |
| S355J0 | 0.24 max | 0.60 max | 1.70 max | 0.040 max | 0.040 max | 0.60 max | 0.014 max |
mechanical properties:
| Grade | Yield strength ReH/(N/mm2) (t≤16mm) min | Tensile strength Rm/(N/mm2) (3mm≤t≤16mm) | Elongation A/%(3mm≤t≤40mm) min | Charpy V test | |
| Temperature/℃ | Impact energy (Longitudinal)/J min | ||||
| S355J2 | 355 | 450-680 | 22 | -20 | 27 |
| S355J0 | 355 | 450-680 | 22 | 0 | 27 |
Charpy Impact Test:
S355J0: Requires a minimum impact energy of 27 Joules at 0°C.
S355J2: Requires a minimum impact energy of 27 Joules at -20°C.
Summary:
S355J0 is suitable for applications where the temperature does not fall below 0°C, making it ideal for mild climate conditions.
S355J2 is designed for colder environments, with superior toughness at temperatures as low as -20°C.
