| Abstract Scope |
For VIRGINIA Class Submarines, General Dynamics Electric Boat (GDEB) currently uses labor-intensive manual Gas Tungsten Arc Welding (GTAW) operations for piping, ship structures and tanks. Manual GTAW is relatively slow, particularly for large diameter circumferential welds. Also, manual GTAW requires a high level of skill due to the dexterity required to use both hands independently. A complementary process, Gas Metal Arc Welding (GMAW), is used for structural welding. GMAW has the advantage of high deposition rates, but it is susceptible to higher levels of porosity than GTAW, resulting in potential rework. Therefore, a one-to-one substitution of manual GTAW for GMAW is not a viable solution. Numerous shipyards are now replacing manual GTAW with a semi- automatic variant of the GTAW process. This process features an automatic “hot-wire” filler metal feed that replaces the legacy manual hand fed wire into the weld pool. Initial development demonstrated welding process improvements upwards of 30% for various welding applications in the shipyard.
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