S355J2 and S355K2 steel plates are under same standard, EN10025-2. EN S355 steel offers high yield (minimum yield strength of 355 N/mm²) and tensile strength. It is a structural grade steel which is widely used in engineering and construction industries. EN S355 steel can be supplied with a variety of treatments and test options to ensure that it is a highly usable steel in your various projects.
Here's a breakdown of the codes:
S: Structural Steel.
355: Minimum yield strength in MPa (e.g., 355 N/mm²).
J2W / K2W: Impact test performance at -20°C.
W: Weathering steel (improved atmospheric corrosion resistance).
S355J2W and S355K2W steel plates have same chemical composition and strength as below:
355J2W and S355K2W steel plates chemical composition:
| Thickness (mm) | C | Mn | Si | P | S | N | Cu |
| under 40 | 0.2 | 1.6 | 0.55 | 0.025 | 0.025 | - | 0.55 |
| >40 | 0.22 |
S355J2W and S355K2W steel plates chemical composition:
| ReH Minimum Yield strength (MPa ) | R m (MPa) | ||||||||||||
| for nominal thickness(mm) | for nominal thickness (mm) | ||||||||||||
| <16 | =>16 | >40 | >63 | >80 | >100 | >150 | >200 | >250 | <3 | =>3 | >100 | >150 | >250 |
| ≤ 40 | ≤63 | ≤ 80 | ≤100 | ≤150 | ≤200 | ≤250 | ≤400 | ≤ 100 | ≤150 | ≤250 | ≤400 | ||
| 355 | 345 | 335 | 325 | 315 | 295 | 285 | 275 | 265 | 510-680 | 470-630 | 450-600 | 450-600 | 450-600 |
However, It mainly lies in their impact test:
J2W symbol Charpy V-Notch Impact Tested Longitudinal 27 Joules at -20 ˚C under 150mm thickness.
K2W symbol Charpy V-Notch Impact Tested Longitudinal 40 Joules at -20 ˚C max 100mm thickness.
S355K2W steel plates Charpy V-Notch Impact Tested Longitudinal 40 Joules at -20 ˚C, S355J2W steel plates Charpy V-Notch Impact Tested Longitudinal 27 Joules at -20 ˚C under 150mm thickness. S355K2W steel plates are good in highly impact under low temperature condition projects.
