سال انتشار: ۱۳۸۶

محل انتشار: هشتمین کنفرانس ملی جوش و بازرسی ایران

تعداد صفحات: ۸

نویسنده(ها):

Masood Aghakhani – Welding Research Center, Department of Mechanical Engineering, College of Engineering University of Razi

چکیده:

In gas metal arc welding (GMAW) , selecting appropriate values for process variables is essential in order to control input into the workpiece from which reliable predictions can be made about the metallurgical and themechanical properties of welded joints and the same time get the required bead size and quality. Also, conditions must be selected that will ensure a predictable and reproducible weld bead, which is critical for obtaining high quality. In this investigation on gas metal arc welding of aluminum , it was observerd that the welding current was effected by any change in wire feed speed, welding voltage, and nozzle-to-plate distance. To determine accurately the welding current for any set of these parameters, a mathematical model has been presented. The model was developed using s two-level factorial technique and its adequacy was tested by the ANOVA method.
The estimated and observed values of the welding current have shown on a scatter diagram and the interaction effects of different parameters involved have been presented in graphical forms. These results can be utilized for determining accurately the heat input into the workpiece fromm which reliable predictions can be made about the matellurgical and the mechanical properties of welded joints. The study revealed : 1)In GMAW, the welding current in effected not only by the wire feed speed but also by the welding voltage and the nozzle-to-plate distance; 2. At low wire feed speeds, the effect of welding voltage on welding current was negligible . However, it increased enormously at higher wire feed speed ; 3) Increase in the nozzle – to – plate distance resulted in the increase in welding current possibly due to the increase in the arc length ; 4) Increase in the welding voltage resulted in increase in the welding current , indicating a rising V-I characteristic of the welding arc.