Mapeamento paramétrico da soldagem GMAW com arames de aço inoxidável ferrítico e austenítico

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The use of stabilized ferritic stainless steel wires for GWAW welding in the industry has been increasing in the last years, replacing austenitic stainless steel wires for the welding of stabilized ferritic stainless steel. Besides its lower costs, the ferrític stainless steel weld present a similar, or even superior quality compared to austenitic welds. Considering that this development is relatively recent, there is still a small number of publications related to it, particularly in our country, and this may be a factor hindering a broader application of this consumable in the industry. The present work intents to contribute to increase the knowledge related to the application of these wires to the welding of the stabilized ferritic stainless steels. Two stabilized ferritic stainless steel wires, one of them stabilized with Ti (430Ti) and the other with Nb (430LNb), and one austenitic (308LSi), with nominal diameter of 1,00mm, were utilized for bead-on-plate welding tests of bistabilized ferritic stainless steel (439) plates 5.0 mm thick. Firstly, the wires were characterized in terms of their chemical analysis, surface quality, mechanical properties, cast and helix and electrical resistivity. In the welding trials, the wire feed rate was varied from 2 to 12 m/min and the voltage from 12 to 32 V to obtain the three main kinds of metal transfer (short circuit, globular and spray). The shielding gas mixture was Ar2%O2 and the flow rate 15l/min. The current and voltage were monitored by a data acquisition system. The data were analyzed by the SINAL program which was developed in the LABSEND (UFMG). Several aspects like current, current standard deviation, short circuit time, and others were compared for the three wires in order to analyze different aspects of the process, including its relative stability. Metal transfer maps were built in terms of voltage and feed rate. The results were verified through high speed filming. It was verified that welding with the 430Ti wire tends to present less stability. The weld beads obtained with this wire showed a poorer bead aspect when compared with the others. One possible reason is its significant inferior surface quality.

ASSUNTO(S)

metalurgia de transformação teses. engenharia metalúrgica teses. arame teses. engenharia de minas teses.

ACESSO AO ARTIGO

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