Application of impact tensile testing to welded thin sheets

The resistance of the vehicle in the case of collision and fuel consumption are naturally a major concern in car industry. The behaviour of welded structures or base metals during dynamic loading, reproducing the conditions of collision, is of special importance. This necessitates the evaluation of welded thin sheets submitted to the dynamic loading in order to correlate in real service conditions. The main objective of this study is to examine the mechanical and metallurgical behaviour of the weld bead, heat affected zone (HAZ) and base metal for thin sheet steels used in the car industry by using a new type of impact tensile test (ITT) in point of view of the energy level and fracture mechanism. It is examined also in detail the basic principles of ITT in order to give precise data for the crash test. A special geometry of the specimen to be tested is composed of two different parts, a smooth and a notch section adapted to welds and base metals. Moreover, an intensive study has been taken to correlate the determined ITT transition temperature from this test with the familiar Charpy V transition temperature at the 28 J level in Charpy V test.