No abstract

Duplex stainless steels 2205 are widely used in constructional and petrochemical applications because of their good mechanical and corrosion properties. The objective of this work was to study the influence of aging at high temperature on the austenite and d ferrite equilibrium. After welding by TIG process, duplex stainless steel was aged in the range of 800 – 1150 °C temperatures for 60 min. The microstructure was characterized by metallography and X-ray methods. The toughness of welded structure was also measured.

The thermal history of a weld joint produced by gas tungsten arc welding process (TIG) is analyzed using two dimensional finite volume method . One of the fundamental problems in the analysis of heat flow during welding consists in defining welding heat source model. In our analysis the heat source is approximated by the Gaussian distribution for the heat flux delivered by the welding arc. Temperature-dependent thermal properties and convective and radiative surface thermal conditions are considered. Computations are carried out for butt welding of two thin plates of carbon steel and austenitic stainless steel. To assess the accuracy of the model, the computed sizes of the heat affected zone and melt pool zone are compared with available experimentally measured values. The results indicate good agreement.