Resumo

MUSAUEL, C et al. Evaluation of the setting up of a system of residual water treatment in a tobacco company. Rev. Fac. Ing. UCV [online]. 2006, vol.21, n.2, pp.61-73. ISSN 0798-4065.

When a 2205 duplex stainless steel component is welded, the precipitation of detrimental minority phases could ocurr as result of thermal cycle which the piece is exposed. In this study, microstructural characterization by optical and electronic (scanning and transmition) of a 2205 duplex stainless steel 5 mm thickness sheet joint, welded by gas metal arc welding process was achieved, using the pulsed arc technique (GMAW-P), adding consumable material and the postwelding cooling was carried out at two different ambient (air and water) ¹. The microestructural study included volumetric fraction phase’s measurements, heat affect zone width, the morphology and chemical composition of the phases and precipitates present, and the identification by transmition electronic microscopy (MET) in way of image in clear field and electron diffraction additionally a hardnesses measure throughout all welded joint was made. In conclusion it was demonstrated that the speed of cooling is a determining factor of the volumetric fractions, the morphology of the phases majority, ZAC´s wide, precipitated present and hardness of the welded joint, being the water cooling less detrimental for welded DSS 2205 in reference to wide of the zone affected by the heat (ZAC) and the possible massive precipitation of detrimental phases.

Palavras-chave : Duplex; 2205; GMAW; Characterization.