Study on Behaviour of Molten Pool in Arc Welding (3rd Report)

Mathematical Modelling of a Molten Pool in Arc Welding of Thin Plate

Abstract

A simple mathematical model for arc welding of thin plate is developed in this paper.
The calculation model, used in this work, is divided into two phases. In the first phase, the heat flow in base metal is numerically analyzed in order to estimate the molten pool size. In the second, the surface tensional balance equation is numerically analyzed to obtain a theoretical configuration of molten pool and weld geometry.
In the first part of this report, some typical phenomena in thin plate arc welding are simulated by the computational model and it is made clear that the computed results are quite satisfactory in a qualitative sense.
In the second, the computed tolerance zone of process parameters, derived from the critical conditions of the lack of fusion and the burn-through, has been compared with the experimental one in thin plate TIG arc welding and a good correspondence has been obtained between the model analysis and the experiment.
Consequently, it is concluded that the mathematical model, used in this work, is a useful guide to optimum process parameter in thin plate arc welding.