THE INFLUENCE OF SPECIMENS CUTTING DIRECTION ON THE CRACK RESISTANCE OF SURFACE WELD METAL

It is well known that the mechanical properties of materials depend of the rolling direction, which means that the direction of specimen cutting affect the obtained values. This feature also exists in the welded joint, where the anisotropy is caused by direction of the deposit welded layers. One high-carbon steel is surface welded by flux-cored wire and specimens were cut in order to determine the toughness and crack growth parameters for longitudinal and transversal directions. Total impact energy, crack initiation energy and crack propagation energy were estimated at room and lower temperatures. It is shown that at all temperatures higher toughness values were obtained for specimens cut from the transversal direction, i.e. with notch in welding direction. Also in this case were obtained higher threshold values and lower fatigue crack growth rate, indicating a better resistance to crack growth.