Microstructure and Properties of the Welded Joints of SAF2205/16MnR Duplex Stainless Steel Composite Plate

The welding technology of the composite plate of SAF2205 duplex stainless steel and 16MnR steel was studied. The base metal was welded with E5015 welding rods by shielded metal arc welding (SMAW),and transition region and clad metal were welded with ER2209 welding rods by tungsten inert gas arc welding (TIG). The tensile property,microstructure and phase compositions of joints had been analyzed by means of tensile machine,scanning electron microscopy,optical microscopy and X-ray diffraction,etc. The results show that the tensile strength of the joints was 512 MPa,and the microstructure transition between clad metal/heat affected zone/transition layer weld was mild,and biphase proportion of austenite and ferrite was in the required range. The short distance diffusion of alloy elements near the dissimilar steel fusion zone didnt obviously occur. There was also no precipitation of σ phase and M23C6 in the weld metal,which is advantageous to mechanical properties and corrosion-resistance of the joints.