The use of underwater wet welding for offshore repairs has been limited mainly because of porosity and low toughness in the resulting welds. With appropriate consumable design, however, it is possible to reduce porosity and to enhance weld metal toughness through microstructural refinement. New titanium and boron-based consumables have been developed with which high toughness acicular ferrite (AF) can be produced in underwater wet welds. Titanium, by means of oxide formation, promoted an increase in the amount of acicular ferrite in the weld metal, while boron additions decreased the amount of grain boundary ferrite (GBF), further improving the microstructure. Porosity reduction was possible through the addition of calcium carbonate at approximately 13 wt percent in the electrode coating. However, weld metal decarburization also resulted with the addition of carbonate.

Issue Section:
Research Papers
Topics:
Design, Metals, Ocean engineering, Welding, Ferrites (Magnetic materials), Fracture toughness, Porosity, Boron, Titanium, Welded joints, Coating processes, Coatings, Decarburization, Electrodes, Grain boundaries, Maintenance
1.
Chew
B.
,
1973
, “
Prediction of Weld Metal Hydrogen Levels Obtained Under Test Conditions
,”
Welding Journal
, Vol.
52
, pp.
386s–391s
386s–391s
.
2.
Frost, R. H., 1992, “Influence of Solidification on Inclusion Formation in Welds,” 3rd International Conference on Trends in Welding Research, Gatlinburg TN, June 1-5.
3.
Gooch
T. G.
,
1983
, “
Properties of Underwater Welds, Part 2: Mechanical Properties
,”
Metal Construction
, Vol.
15
, No.
4
, pp.
206
–
215
.
4.
Grubbs, C. E., and Seth, O. W., 1972, “Multiple Pass All Position Wet Welding: A New Tool,” Offshore Technology Conference, OTC 1620.
5.
Ibarra, S., Olson, D. L., and Grubbs, C. E., 1989, “Underwater Wet Welding of Higher Strength Offshore Steels,” 21st OTC, Houston, TX, May 1-4, OTC 5889 pp. 277–282.
6.
Ibarra, S., Olson, D. L., and Liu, S., 1992, “Effect of Water Depth on Underwater Weld Metal Porosity Formation,” International Conference on Underwater Welding, AWS pp. 54–69.
7.
International Institute of Welding, 1988, “Guide to Light Microscope Examination, IIW Doc. No. IX-1533-88, IXJ-123-87, Revision 2, June.
8.
Lancaster, J. F., 1987, Metallurgy of Welding, 4th Edition, Allen & Unwin, London, U.K., p. 178.
9.
Oh
D. W.
, and
Olson
D. L.
,
1990
, “
The Influence of Boron and Titanium on Low-Carbon Steel Weld Metal
,”
Welding Journal
, Vol.
69
, No.
4
, pp.
151s–158s
151s–158s
.
10.
Suga, Y., and Hasui, A., 1986, “On The Formation of Porosity in Underwater Weld Metal (The First Report), Effect of Water Pressure on Formation of Porosity,” IIW Doc. IX-1388-86, American Council, AWS, Miami, FL.
11.
Watson, P. D., Dexter, R. J., and Schick, W. R., 1990, “Underwater Welding: A Literature Search, Southwest Research Institute, Project 06-2472, May.
This content is only available via PDF.
Copyright © 1995
 by The American Society of Mechanical Engineers
You do not currently have access to this content.