Charpy Impact Testing

Charpy impact testing is a fundamental mechanical test that measures the energy absorbed by a standard notched specimen during fracture under a single high-strain-rate impact. The results quantify the notch toughness of the material - a critical property for assessing the risk of brittle fracture in structural steels, pressure equipment and welded fabrications.

QMS Asset Integrity performs Charpy V-notch impact testing at our mechanical testing laboratory, serving welding procedure qualification, welder qualification, material certification and production quality control requirements across the oil and gas, marine, mining, defence and manufacturing sectors.

Testing can be performed at ambient temperature or at specified sub-zero temperatures to characterise the ductile-to-brittle transition behaviour of ferritic steels - essential data for equipment operating in low-temperature or cryogenic service.

A standard Charpy V-notch specimen (55 mm long, 10 mm square cross-section with a 2 mm deep 45-degree V-notch) is positioned on supports in the testing machine. A calibrated pendulum of known mass is released from a fixed height, striking the specimen on the face opposite the notch.

The energy absorbed during fracture is measured in Joules from the difference in pendulum height before and after impact. Three specimens are typically tested at each specified temperature and the results averaged. Additional data including percentage shear (crystallinity) and lateral expansion may be reported as required.

For transition curve work, sets of specimens are tested at multiple temperatures to map the energy absorption from the upper shelf (ductile) through the transition zone to the lower shelf (brittle).