Ultrasound Influence on Materials Structure in Parts Reconditioned by Welding with Ultrasonic Field

D. Dobrota, Engineering Faculty, University “Constantin Brâncuşi” of Târgu-Jiu, Romania, Gh. Amza, Engineering and Tehnological Systems Management Faculty, Polytehnic University of Bucharest, Romania, Research presented in the paper refers to the structural analysis of materials that are thermally infl uenced for loading by welding of pieces in the classical variant of manual coated electric arc welding and the version that in which the welding bath is activated by ultrasounds. The structural analysis made refer to: the size of the grains of the structure obtained under certain loading conditions through welding, grain size variation on the submission of a single layer in the ultrasonic fi eld, the mode of solidifi cation and fragmentation of grains when loaded in welding in a ultrasonic fi eld, acceleration of the diff usion process for ultrasonic activation, the appearance of hard carbides between grains.