Effect of water depth on the underwater wet welding of ferritic steels using austenitic Ni-based alloy electrodes
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 2000
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 41
Description: Underwater welding using shielded metal arc welding (SMAW) on US naval Vessels is very attractive because of the ability to effect repairs without costly dry dock expenses. In the past the primary problems with underwater wet weldments on steels utilizing SMAW with ferritic electrodes, were underbead cracking in the heat affected zone (HAZ), slag inclusions, oxide inclusions, and porosity. To avoid underbead cracking three weld samples were made using an austenitic nickel weld metal with an Oxylance coating at 10 feet of salt water, 25 feet of salt water, and 33 feet of salt water. A final sample was made using austenitic nickel weld metal with a Broco coating at 33 feet of salt water. Because of the ductility of the austenitic nickel weld metal no underbead cracking occurred, however porosity and high inclusion counts were found in all four samples. The average size of the inclusion increased with increasing depth. The Broco sample exhibited far greater porosity than did the 0xylance samples. This work addresses quality of the welds, mechanisms for the formation of the inclusions, and analysis of the difference between the Oxylance and Broco weld rods.
Notes: Thesis advisor(s): Fox, A.G.;

Thesis (M.S. in Mechanical Engineering) Naval Postgraduate School, Sept. 2000.

Includes bibliographical references (p. 39)

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dk/dk cc:9116 12/11/00.