slagprøving

Slagprøving is a mechanical testing method used to determine a material’s toughness when subjected to a sudden, high-rate load. The test is common in metallurgy and materials engineering and is often referred to in English as impact testing. It assesses the energy a material can absorb before fracturing, providing an indication of its resistance to brittle failure at different temperatures and microstructures.

In the test, a notched specimen is struck by a pendulum hammer in a controlled setup. The most widely used configurations are the Charpy and Izod tests. In Charpy, a notched rectangular bar is supported at its ends and struck on the opposite side; in Izod, the specimen is mounted differently so the hammer strikes the notch directly. The energy absorbed by the specimen to fracture is determined from the difference in potential energy of the pendulum before and after impact, and is usually reported as the impact energy in joules or as kilojoules per square meter (kJ/m^2) when normalized to cross-sectional area.

Tests are conducted over a range of temperatures to produce a toughness profile, including the brittle-to-ductile transition for many metals. Results are influenced by notch geometry, specimen size, material condition, and testing speed. Slagprøving is used for quality control, material selection, and to evaluate heat treatments, welding regions, and alloy compositions.

Standards for Charpy and Izod impact testing are provided by international bodies such as ISO and ASTM, with specific requirements for specimen geometry, preparation, and reporting. While informative for comparing materials, slagprøving is one of several tests necessary to fully characterize toughness under real-world loading conditions.