Author : Ajay Kumar

Angular distortion is a major problem and most pronounced among different types of distortion in the butt welded plates. This angular distortion is mainly caused by the non-uniform extension and contraction through thickness direction due to the temperature gradient. Restriction of this distortion by restraints may lead to higher residual stresses. However, if the magnitude of the angular distortion is predictable, these can be reduced by providing initial angular distortion in the negative direction. It is difficult to obtain a complete analytical solution to predict angular distortion that may be reliable over a wide range of processes, materials, and process control parameters. Presently, several analytical methods and empirical formulas have been developed to give quantitative information. In this study, the statistical method of three factors, two level full factorial designs has been used to develop mathematical model to correlate angular distortion in metal inert gas. The distortion is found to be significantly influenced by no of passes, time gap between successive passes and joint gap. Direct and interaction effects of the process parameters are also analyzed and presented in the graphical form.

Keywords: Welding, Distortion, Statistical design.

Article published in International Journal of Current  Engineering  and Technology, Vol.1,No.1 (Dec. 2011)