The effects of hybrid welding parameters on porosity formation in the fillet joint have been investigated with the shop primer-coated AH36 steel used in shipbuilding industries. The X-ray transmission images for fillet joints revealed that most of the porosities were observed near the back bead and had elongated shapes. From EPMA results of porosities, it was believed that the Zinc metal contained in the shop primer was not the main reason for porosity formation. Instead, from the investigation on the behavior of the molten filler metal in the keyhole, porosities near the back bead were attributed to a neck collapse of the keyhole which resulted from excessive amount of molten filler metal.

Topics
Transition metals, Welding
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© 2005 Laser Institute of America.
2005
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