2006 Volume 24 Issue 4 Pages 368-372
There is need for speeding up of MAG welding to improve productivity but it is known that irregular bead is formed more easily as welding speed increases. A simulation model for the welding is very useful to predict the forming of welding defects. In the present work, a three dimensional (3-D), non-stationary thermal conduction model for thin plate is developed. The temperature distribution in the base metal is calculated to estimate the molten pool size using a finite difference model based on the 3-D heat conduction equation, and the surface profile of the molten pool is calculated taking account of the balance of gravity, surface tension and arc pressure. As a result of comparison between experiment and calculation, it is shown that the proposed model is useful as an engineering tool to predict the high speed MAG welding. Additionally, it is shown that the proposed model is effective to clarify the mechanism of the bead formation in the high speed MAG welding.
