INFLUENCE OF WELDING PARAMETERS ON CHARACTERISTICS OF WELDMENTS DURING STRUCTURAL STEEL PULSE MIG OVERHEAD WELDING

Abstract

The work carried out in this project deals with the arrangement of experimental setup, collection of data for the working range of different variables and study of influence of different pulse parameters like pulse width, peak current, frequency on the mechanical properties and the bead geometry of overhead position V-groove welds during gas metal arc welding using Ar+2%02 as a shielding gas. Copper coated mild steel wire of specification (SFA-5.18-89 ER 70S-6) of 1.2 mm has been used as a filler wire in this investigation for bead deposition. The mean current and voltage has been kept constant and pulse width, peak current & frequency has been varied while keeping other two same. The bead on plate deposits and V-groove welding has also been carried out at 0 Hz (conventional MIG) and the characteristics of weld deposit have been compared with that produced by pulsed current process. The superiority of gas metal arc welding using pulsed current over continuous current short — circuiting mode of metal transfer in overhead weld has been marked by significant enhancement in tensile, impact & fatigue properties of weld joint. It primarily happens because during pulsed current gas metal arc welding, the variations in pulse parameters affect the geometry of weld deposit and mechanical properties of weld