Morfologia do revestimento pelo processo de arame tubular utilizando tecimento semiautomático

Abstract

This work aimed to study the geometric and morphological characteristics of the weld bead obtained by MIG / MAG welding process using tubular wire 410 NiMo MC, with semi-automatic weaving and using pulsed current. The first step consisted of exploratory tests to determine control factors and their levels to be used in the stage called "definitive experiments " In the final experiments to determine the number of tests to be performed, we opted for the use of the statistical method of Taguchi (robust design of experiments) , in order to comply with a limited number of tests , aimed to obtain the influence of control factors (welding parameter) on the response variables ( geometric characteristics of the weld beads ) . They chose three control factors each with two levels: Width, pitch and current by varying the current between 200 A and 230 A, resulting in a total of 4 tests. The welds were performed in the flat position by simple deposition on ABNT 1020 steel sheet was maintained constant flow of shielding gas, the feed rate and DBCP. After welding the samples also underwent ultrasound testing, macrograph, Vickers hardness and morphological analysis in the coating. The results showed that the highest current values were used to significantly alter the geometry of the weld bead by increasing the dilution and penetration welding in coat.