Abstract:
The element transfer of Ti from molten flux to the weld metal is limited to less than 310 ppm
Ti in the submerged arc welding of carbon steel. This limitation is due to the high oxygen partial
pressure prevailing at the molten flux-weld pool interface. Our previous study illustrated that the
use of Al powder in combination with Ti powder improves the transfer of Ti to the weld metal to 4%
Ti, whilst maintaining 509 ppm O in the weld metal. The weld metal ppm O should be controlled at
200 to 500 ppm O to maintain weld metal toughness. In this study, the addition of Cu powder with
Ti and Al powder is applied to illustrate the stabiliser effect of Cu in the weld pool. The role of Cu as
weld pool stabiliser is due to its decrease of the temperature required to melt Ti into the weld pool,
so increasing the quantity of metal powder melted into the weld pool. The weld metal composition
improved to 5.1% Ti, 3.6% Cu, and 371 ppm O. Thus, the role of Al in controlling the partial oxygen
pressure at the molten flux-weld pool interface is maintained in the presence of Cu powder.
