Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Effect of the water in the contact tip in underwater FCAW
Submission Author:
Marcelo Teodoro Assunção , MG
Co-Authors:
Marcelo Teodoro Assunção
Presenter: Marcelo Teodoro Assunção
doi://10.26678/ABCM.COBEM2017.COB17-0694
Abstract
Underwater welding is an important process employed to repair offshore and marine structures with advantages of not handling the components off the water. However, the process is performed with lower stability in comparison with welds performed in open air. Under the water, the welding arc is surrounded and compressed by water. When flux cored arc welding - FCAW - is performed in wet condition, water fills the gap between the contact tip and the tubular wire, resulting in a worse current transfer, reducing the process stability. In the present work, with the view to improve the stability of underwater FCAW with self-shielding electrode, a welding torch was developed at LRSS-UFMG. The torch has a sealing system that insulates the contact tip from the water, so that a fraction of the wire length called stick out is kept dry inside the device. A two-level factorial design was used for experimentation and an Analysis of Variance was conducted to validate the results. Current coefficient of variation was used as the index of stability. Welds performed with the torch have shown more stable arc in comparison to beads deposited with no mechanical barrier between water and the contact tip.
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