Welding Phenomena during Vertical Welding on Thick Steel Plate using Hot-wire Laser Welding Method

Abstract

The objective of this research was to develop a single-pass vertical welding process for thick steel plates using hot-wire laser welding to reduce the heat input. A laser diode with a large rectangular beam spot and twin hot-wire feeding system were used. Welding phenomena were investigated using stationary and weaving laser irradiation with small and large groove widths. Single-pass vertical welding for thick steel plates with a low heat input and low dilution could be achieved. A critical energy density existed for each welding speed at which fusion of the groove surface could commence. The energy density affected fusion of the groove surface compared with welding speed. Weaving laser irradiation made it possible to maintain a high energy density and accommodate the large gap variation.