Super-TIG 육성용접에서 모재 온도와 비드퍼짐비의 관계에 관한 연구

Abstract

Overlay welding is applied to a number of industrial fields such as off-shore plant field, nuclear power plant field, various power generation facilities, heavy machinery and large diesel engine etc. The overlay is developing continuously and its demand is also increasing. Therefore, high productivity and high quality welds must be obtained. LF(Lack of fusion) occurs frequently in the vicinity of the overlapped part of the bead, and one of the causes is the low spreadability of the bead. If the bead spreadability is poor, there arises a problem that the deviation between the top and the valley of beads becomes large. In this study, the variation characteristics of the bead spread ratio according to the base metal temperature change were investigated using Super-TIG welding with very high productivity. As the preheating temperature of the base metal increases in the same OS width, the formed bead width increases proportionally. The deviation of the height of the top and the valley in room temperature was 0.63mm, and the height deviation of the top and the valley was decreased 0.24mm in the base metal preheated with the 150℃.