Abstract:
2205 duplex stainless steels( DSS) were welded by gas-shielded flux-cored wire,and the welded joints are conducted by solution treatment. The microstructures and fracture morphology of weldied joints were analyzed by means of OM,SEM and EDS. The impact toughness and microhardness of welded joints were tested and analyzed systematically. The results show that the fusion zone of untreated welded joint represents a large width,and the organization is mainly composed of ferrite with coarse grains. Few of
χ phases precipitate at ferrite-austenite grain boundaries and some carbide appears inside ferrite in heat affected zone( HAZ). σ phase and γ
2 phase precipitate inside ferrite in weld.After 1 050 ℃ solid solution treatment,precipitated phase and carbide disappear and the proportion of austenite is higher,which results in high impact toughness and low microhardness,and the number of equiaxed dimples increase in the impact fracture surface.