1.S355JR, S355J0 and S355J2 are different grades of European standard channel steel. The letters behind them represent the impact toughness of the steel at different ambient temperatures.
2.S355JR: "JR" means that the steel has low temperature impact toughness and is suitable for conventional environments. The impact energy is ≥27J at 20℃, but the performance may be insufficient in low temperature environments.
3.S355J0: "J0" indicates that the steel has zero-degree impact toughness, which means that it performs stably and reliably in environments at or above zero degrees.
4.S355J2: "J2" means that the steel still has excellent impact toughness at -20℃, has better applicability and stability in cold environments, and is often used in engineering projects that need to resist low-temperature impact.
5. In terms of mechanical properties, the yield strength of these three steels all reaches 355MPa, but due to different chemical compositions and heat treatment processes, their tensile strength, hardness, toughness and other properties will still be different.
Therefore, when choosing which steel to use, it is necessary to make comprehensive considerations based on specific engineering requirements and environmental conditions.
