Estudo da técnica de enchimento de chanfro do aço naval pelo processo GMAW-CW

Abstract

In this work studied the operational viability and the characteristics economic and geometric of technique of the process welding GMAW -CW (additional alimentation of a cold wire) in comparison Gas Metal Arc Welding (GMAW). The alimentation system of cold wire was designed and adapted to welding gun GMAW. Used an electronic source of multiple processes adjusted in constant voltage and DC+, the gas shield was a mixture 75% Ar+25% CO2 and commercially pure CO2. The wire used was Class ER70S-6 with diameter of 1.2 mm for the electrode wire and 1.0 mm for the cold wire, the both wires were fed in heads independent. The input operating variables were the feed speed of wire energized at three levels, 4, 6 and 8 m / min and the wire feed speed in cold 50%, 60% and 70% of the wire feed speed energized . The welds were automated in simple deposited in the pushing direction and the positioning of the cold wire in a single level, Tandem in chamfer "U" steel plate ASTM 1020. The variables of response used were: superficial inspection of the cords, analysis of the geometry (width, penetration, reinforcement and dilution) and economic solder (melting rate, deposition rate, yield and operating cost). The results indicated that for surface analysis, using the AR25% CO2 gas to the surface of the strands were more homogeneous with respect to CO2 and less splash index for the analysis of economic characteristics, the process always GMAW-CW was superior to the conventional process, the operating costs the conventional process was lower, but without filling of the chamfer, which occurred with the use of GMAW-CW.