SOME IMPROVEMENTS IN SELF-SHIELDED FLUX CORED ELECTRODES FOR ARC WELDING

A fundamental study has been conducted in Japan on reducing the atmospheric gas content of self-shielded flux-cored arc-welding electrodes, in order to improve the impact toughness of the weld metal. The effect of various factors on arc and gas abosrbing phenomena has been elucidated and the quality of commercial electrodes improved. Making the electrode cross-section more complex and the size as fine as possible succeeded in minimizing the gas content and improving the quality of the weld metal. In commercial electrodes, reducing tha A1 content to improve weld-metal toughness was achieved by adopting a constant potential dc power source. In addition, reducing the welding fumes and using surface treatment without hydrogen-forming materials have greatly improved the usability of the electrodes.