Wet underwater welding trials with commercial manual metal arc electrodes
- TWI, Cambridge (United Kingdom). Materials Dept.
- Ministry of Defence, Bath (United Kingdom)
Six commercial wet underwater welding manual metal arc electrodes were evaluated in trials which simulated repairs to structures in shallow water. Welding was carried out both vertically down and overhead, at a depth of approximately 5 meters. One of the electrodes was an austenitic stainless steel, and the remainder were ferritic steel, containing low levels of carbon and manganese. Two weld configurations were employed in 8 mm thick C-Mn steel plate. Each weld was radiographed, sectioned, and examined metallographically. Tensile, Charpy and hardness testing were carried out. The trials revealed significant differences in the handleability of the six commercial electrodes. Handleability was better when welding vertically than when welding overhead, and was also better for fillet welds than for butt welds. Worm-holes and porosity were common in the latter. Extensive cracking occurred in the panels welded with the stainless steel electrode, preventing the extraction of mechanical test specimens from them. For the weld metal of the ferritic steel butt welds, strength and hardness increased with increasing alloying. Weld metal Charpy toughness varied widely between the different deposits. HAZ toughness was higher than that of the weld metal, but followed the trend of the weld metal data. On the patch plates, failure occurred in the parent steel on cross weld tensile specimens for the ferritic consumables, and in weld metal for the panels welded with the stainless steel electrodes. Viewed overall, two of the ferritic electrodes gave the best handleability and mechanical properties. However, fine-scale cracking was observed in the vertical butt weld deposited with one of them, and thus the other ferritic electrode gave the best all-round behavior. The remaining electrodes showed poorer handleability and a higher incidence of weld defects, including the extensive cracking observed in the butt welds produced with the stainless steel electrode.
- OSTI ID:
- 403604
- Report Number(s):
- CONF-9606279--; ISBN 0-7918-1492-0
- Country of Publication:
- United States
- Language:
- English
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