Resumen

BAIXO, Carlos Eduardo Iconomos  y  DUTRA, Jair Carlos. Effect of shielding gas and transfer mode on the application of 625 alloy in carbon steel. Soldag. insp. (Impr.) [online]. 2009, vol.14, n.4, pp. 313-319. ISSN 0104-9224.  http://dx.doi.org/10.1590/S0104-92242009000400005.

In this study the effect of shielding gas (Ar, Ar/CO₂, Ar/O₂ and Ar/He/O₂) and transfer mode (short-circuit and pulsed current) in MIG/MAG welding with ER-NiCrMo-3 wire to produce bead-on-plate deposits and root passes in "V" joints of ABNT 1020 steel were analyzed. The most favorable results in root pass welding were obtained with pulsed current, employing a "V" joint with a 90º aperture and Ar+25%CO₂ atmosphere. The use of shielding atmospheres with 20% helium and a low percentage of active gas did not produce the expected results, being effective only in bead-on-plate weld deposition. However, it was not very effective to produce satisfactory results in root pass welding. Poor results were obtained in the welding with short-circuit transfer regardless of the used shielding gas, and when an atmosphere of pure argon was used, regardless of the mode of transfer.

Palabras clave : Nickel Alloys; 625 Alloys; ER NiCrMo-3; GMAW; Root Welding; Recovery.