Charpy Impact Test
A Dynamic Test in which a notched specimen is struck and broken by a single blow in a specially designed testing machine. The values thus obtained are absorbed energy (resistance offered by the test specimen to shear fracture)., the lateral expansion opposite the notch and percentage shear area.
Test temperatures other than room temperature are specified in product or general requirement specifications. The laboratory is well equipped to conduct impact tests up to minus 200c.
About charpy impact Charpy Impact machine is the one in which a notched specimen is broken by a single blow of freely swinging pendulum. The pendulum is released from a fixed height. Since the weight to which the pendulum is raised prior to its swing and the mass of the pendulum are known, the energy of the blow is predetermined. A scale is provided to indicate the energy absorbed in breaking the specimen. The machine is equipped with a fixture to support a test specimen at a precise location so as to facilitate pendulum strike directly opposite the center of the notch.
For impact testing other than at Room temperature, the test specimens are soaked in a media at specified test temperature under controlled conditions, generally deployed low temperature media are chilled fluids, solidified CO2 , Liquid N2 , plus organic solvents having low freezing points.
Handling equipments : Specially designed SELF CENTERING Tongs are used for precise placement of test specimens en-route from cooling bath to machine anvil. The entire cycle of specimen taken from cooling bath, its placement at anvil and subsequent release of pendulum from its latched position and breaking of the sample is completed well within the specified time limit of 5 Seconds. The laboratory has two impact test machines, one each confirming to ASTM E-23 and BS EN 10045-2.
APPLICABLE TEST PROTOCOLS : ASTM A 370, IS : 1757, BS : EN 10045-2.