Influence of Welding Parameters on the Weld Pool Dimensions and Shape in a TIG Configuration

Marine Stadler,Jean-Jacques Gonzalez,Pierre Freton

doi:10.3390/app7040373

Abstract

The weld pool shape created by the plasma arc interaction on a workpiece depends on many geometrical and physical parameters and on the operating conditions. Theoretical models are developed in such a way as to predict and to characterize the material. However, these models first need to be validated. Experimental results are hence proposed with parametric studies. Nevertheless, the interaction time is often short and the weld pool shape evolution not presented. In this work, the experimental setup and the diagnostic methods characterizing the workpiece are presented. The weld pool shape was evaluated versus time according to several parameters such as the current intensity value, the distance between the two electrodes, the cathode tip angle or the plasma gas nature. The results show that the depth-to-width ratio alone is not enough to compare the impact of the parameters. The analysis points out the great influence of the current intensity on the increase of the width and depth compared to the influence of the value of the cathode tip angle. The rise of the arc length leads to an increase of the power through a higher arc voltage; nevertheless, for distances of three and five millimeters and a characteristic time of the welding process of one second, this parameter has a weak influence on the energy transferred. The use of helium leads to a bigger volume of the weld pool due to an increase of width and depth.

Highlights

In tungsten inert gas (TIG) welding, an electric arc is created between a tungsten electrode and a piece of metal
Effects of the welding parameters on the shape and on the energy transferred to the workpiece are often studied to improve the knowledge of plasma–material interaction in the process [1,2,3,4,5]
Numerous experimental conditions are involved in the TIG process, such as the nature of the shielding gas, the current intensity value, the torch velocity, the volume flow rate and geometrical parameters, such as the distance between the two electrodes or the cathode tip angle

Summary

Introduction

In tungsten inert gas (TIG) welding, an electric arc is created between a tungsten electrode and a piece of metal. Effects of the welding parameters on the shape and on the energy transferred to the workpiece are often studied to improve the knowledge of plasma–material interaction in the process [1,2,3,4,5]. Numerous experimental conditions are involved in the TIG process, such as the nature of the shielding gas, the current intensity value, the torch velocity, the volume flow rate and geometrical parameters, such as the distance between the two electrodes or the cathode tip angle. The study is focused on the welding current intensity, the arc length, the nature of the shielding gas and the tip angle of the cathode

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Results

Conclusion