Measuring absorbed energy with an impact test

The Charpy impact test with pendulum and test piece with regular notch is carried out as indicated by standards.

The impact test is important for establishing the propensity of metallic materials, in this case to resist the dynamic stress caused by impact. This test is also used to define if these materials are suitable for unions that satisfy the PED directive.
During the impact test, the test piece is broken by bending, resulting from the impact with the so-called Charpy pendulum. The machine and the test are sized according to the UNI ENO ISO 148-1 Standard.
The energy available at the start of the test is 300 Joules, and is calculated as the potential energy of the weight lifted to a pre-set height. During the impact test the test piece is struck by the mass at a speed of between 5 and 5.5 m/s, but above all at a pre-set temperature of 23 °C. Finally, the residue energy of the pendulum is measured in order to define how much was absorbed by the test piece.
The impact test is clearly of the destructive type, and is carried out on standardised test pieces with a notch of suitable shape made in the centre.