The Effect of Heat Input on the Weld Metal Toughness of Surface Welded Joint

The welding heat input has a great influence on the weldments properties. This paper describes the influence of welding heat input on the weld metal toughness of high-carbon steel surface welded joint. The steel is surfaced with self-shielded wire, with three different heat inputs (6.5; 10.5 and 16 kJ/cm). Total impact energy, as well as crack initiation and crack propagation energies, are estimate at three testing temperatures. It has been established that with heat input increase toughness decreases and that heat input of 7 kJ/cm is optimal for weld metal toughness of investigated steel. Crack initiation energy is higher than crack propagation energy at all testing temperatures, and due to its temperature insensitivity, these joints have satisfactory and safe exploatation up to -40C.