The objective of the present work is to evaluate the effectiveness of a self-feed device for covered electrodes. This device is able of eliminate disturbances from manual operation or the use of automatic control systems during the study of covered electrode behavior. The conjugation of different methods like short-circuit time statistical analysis, metallographic analysis (penetration, heat affected zone, shape and mean distance between successive solidification fronts) together with the analysis of the electric arc and electrode melting parameters allow us to obtain relationships between arc behavior, mass transfer processes and bead appearance. This permits the extraction of criteria to describe process stability and the behavior of the feed device employed. An appropriate statistical methodology was obtained to process the parameter "duration of short-circuit" through an appropriate adjustment of empirical distributions to a lognormal model. The self-feed device for covered electrode welding allows the repeatable and reproducible execution of welding beads in the flat position, keeping the arc length based on physical and chemistry characteristics of the electrode during welding trials using 125A, 140A, and 160A.
Covered electrodes; operability; self-feed device; statistical processing; electrics parameters
