Full Description

The use of underwater wet welding for offshore repairs has been limited mainly because of porosity in the resulting welds. With appropriate consumable design, however, it is possible to enhance weld metal toughness and reduce porosity. Surface and underwater wet welds, obtained with E6013 grade electrodes modified with systematic titanium and boron additions, were prepared and analyzed to explain in terms of the fundamentals of inclusion formation during weld solidification, any increase in acicular ferrite. It was demonstrated that in underwater wet welding, over 60% vol. acicular ferrite can be obtained, through titanium and boron additions to the electrode covering. The presence of titanium resulted in the formation of inclusions which assisted the formation of acicular ferrite in the underwater welds and countered the rapid quenching effect of the underwater environment. Boron additions decreased the amount of grain boundary ferrite, further improving the microstructure. It was shown that the weld metal titanium and boron compositional ranges for acicular ferrite maximization varied with the heat input and the cooling rate.

Product Details

Published: 1995 Number of Pages: 65 File Size: 1 file , 2.7 MB