Investigation of forming heat affected zone of the deposited weld metal in adaptive-pulse welding in low climatic temperatures

摘要

This article discusses the possibilities of forming the structure of the heat-affected zone (HAZ) in adaptive pulsed welding at low temperatures. It is determined that the use of adaptive pulsed welding allows the formation of a dispersed and uniform structure of the heat-affected zone. In order to identify the effect of current pulses on the formation of HAZ, the same technological parameters of the welding process were maintained. The results showed the possibility of determining the optimal algorithms for adaptive pulse control of welding processes, both positive and negative temperatures. Metallographic studies showed that in all deposited specimens, the weld structures have a dendritic structure: in the zone adjacent to the transition zone in the form of columnar formations, and closer to the outer surface, the dendrites have a disoriented structure. It was revealed that when using adaptive pulsed welding, the grain size in the heat-affected zone is reduced by 1.3 times both at positive and negative climatic temperatures, which undoubtedly positively affects the increase in the strength characteristics of the welded joint.