| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 236556 | Powder Technology | 2014 | 9 Pages |
•Surface discontinuities decrease with increasing FeF2 in the FeS/FeF2 mixtures.•Undercutting defects can be dramatically eliminated by using FeS/FeF2 mixtures.•25%FeS/75%FeF2 produces a welded surface with satisfactory appearance.•75%FeS/25%FeF2 produces a greater increase in joint penetration capability.
The aim of this study is to evaluate the potential of using gas tungsten arc (GTA) welding assisted by FeS/FeF2 mixtures to improve joint penetration and weld quality in joining 316L stainless steel plates. The differences in surface appearance, geometric shape, and out-of-plane deformation of the weldments made by using conventional and activated GTA welding processes have been compared. The effect of FeF2 on the prevention of undercutting produced by using FeS has also been investigated. The results show that the surface discontinuities in the activated GTA weld metal could be decreased by increasing the concentration of FeF2 in FeS/FeF2 mixtures. The concentration of FeS must be greater than that of FeF2 in order for the joint penetration of GTA weldment to be significantly increased. When FeS/FeF2 mixture was used, the molten metal completely filled the melted-out areas of the base metal, thus eliminating undercutting. The results also show that GTA welding assisted by 75%FeS/25%FeF2 produced a greater increase in the weld depth-to-width ratio, resulting in significant reduction of weld-induced deformation in stainless steel weldments.
Graphical abstractWhen 50%FeS/50%FeF2 was used, both inward and outward convections on the surface of the molten weld pool not only increased joint penetration, but also eliminated undercutting.Figure optionsDownload full-size imageDownload as PowerPoint slide
