ELECTRIC ARC IN SHIELDING GAS WELDING SUPPORTED BY ULTRASONIC VIBRATIONS

Abstract

In this work, experimental MAG welding supported by ultrasonic vibrations was studied. Metallo­graphic examination and microhardness were done on the obtained specimens. It was shown that no columnar structure occurs, the typical feature of the arc welding weldments. Also, Widmanstaetten and allotriomorphic ferrite content is decreased, while acicular ferrite content increases. As a consequence, microhardness in the weld metal increases. Finally, decarburization on the surface is decreased, which all indicates an increased crystalli­zation rate with ultrasonic vibrations applied, compared to conventional MAG welding.