Under-Water Cosmetic Resistance Seam Welding of Aluminum Alloys

Common Issues with Seam Welding Aluminum Alloys

• A large quantity of 5000 and 6000 Series aluminum alloys are welded along long seams in the manufacture of a variety of structures such as 53-foot (Approximately 17 meters) long semi-trucks and a host of ocean going vessels
• Arc welded 5000 series structures such as ship decks and semi-truck bodies suffer from a multitude of quality issues
• Magnesium aluminide precipitates formed in the weld heat-affected zones (HAZs) due to the weld heat corrode in salty roads or marine environments
• The welding processes are very expensive, cause much distortion of the welded structure and unreliable weld quality especially at weld starts and ends
• The welded structures also experience much loss of strength due to the weld heat relieving and softening the cold worked material strength in the HAZs
• A large quantity of 5000 and 6000 Series aluminum alloys are welded along long seams in the manufacture of a variety of structures such as 53-foot (Approximately 17 meters) long semi-trucks and a host of ocean going vessels
• Friction-stir welded 5000 series alloy seams also suffer from similar quality issues
• A heterogeneous weld seam that is difficult to inspect non-destructively and contains micro-cracks
• A weld HAZ that is sensitized by the formation of magnesium aluminides that cause corrosion in salty roads and marine environments
• The process is very expensive and weld tool design and maintenance are complicated

IWSL’s New FMRSEW Under-Water Resistance Seam Welding Helps Solve These Quality Issues

• Since the parts welded are water-cooled during welding, the temperatures in the Heat-Affected Zone (HAZ) areas remain cool and magnesium aluminide precipitation does not occur
• The resulting welded structure does not suffer sensitization-corrosion in marine environments or salty roads
• The process is inexpensive and very productive
• The part is welded and cooled in water under good fixturing to minimize weld distortion