EN 10025-2 mandates Charpy V-notch impact testing for UB steel to ensure toughness, with requirements varying by grade suffix:
S355JR: Tested at +20°C, minimum impact energy of 27 J. Suitable for moderate climates (e.g., Western Europe).
S355J0: Tested at 0°C, minimum 27 J. Used in cooler regions (e.g., Northern Europe).
S355J2: Tested at -20°C, minimum 27 J. Ideal for cold climates (e.g., Scandinavia, Canada).Impact testing measures the material's ability to absorb energy during sudden loading, preventing brittle fracture. For example, an S355J2 UB beam in Sweden (winter lows -20°C) will not crack under snow loads, whereas S355JR might fail. Tests follow EN 10045-1, with specimens cut from the flange or web. Results are included in the material certificate, and batches failing the test are rejected. For critical applications (e.g., nuclear facilities), higher impact energy (40 J+) may be required.