Effect of Y₂O₃ particles on mechanical properties of gas metal arc weldments in low carbon steel

In this study, the influence of Y₂O₃ particles on the weld properties of low carbon steel was investigated by metallographic and mechanical tests. It was found that the microstructure of the fuse zone in the weld beam undergoes a significant change after adding Y₂O₃ particles. The amount of allotriomorphic ferrite increases, while that of the acicular ferrite decreases. Moreover, the size of the allotriomorphic ferrite decreases with the adding of the Y₂O₃ particles. On the other hand, the absorbed energy in the Charpy impact test increases, whereas the tensile strength almost keeps unchanged with adding of the Y₂O₃ particles. Furthermore, the hardness of the weld metal is nearly lowered to the level of that of the base metal due to the adding of the Y₂O₃ particles.