MIG welding overlaid austenitic stainless steel on low alloy Q345B. The overlay cladding comprises a transition layer and corrosion resistant layer. Overlaying specimens of transition layer with different thicknesses were prepared. The mechanical properties of joints were tested by micro-hardness, bending test and other methods. The results showed that the mechanical properties of specimen with ER309L welding wire as transition layer did not have splitting phenomena after being bended. There were no cracks. However, the specimen without transition layer had small crack or tiny cracks. When the transition layer thickness is changed, the performance of overlay cladding is essentially unchanged. The organizations of overlay cladding in four groups of specimens are similar, which are composed of austenite and ferrite, and ferrite was mostly distributed in strips and blocks.
