Effect of joint-extrusion-force on the plasticity of beam oscillation fiber laser welded X₂CrTiNb₁₈ ferritic corrosion resisting steels

Abstract The effect of extrusion force on the microstructure and plasticity of the X2CrTiNb18 ferritic corrosion resisting steels joints which were welded by beam oscillation laser welding was studied. The cross section profile of welded joint beam oscillating fiber laser welding & extrusion (OLW&E) was similar to that of the beam oscillation laser welding (OLW), but the weld width of OLW&E was slightly narrow. The differences of microstructure between them were very obvious. In the OLW&E weld zone (WZ), on the one hand, the quantity of small grains increased obviously, and on the other hand they grew in a staggered state. In the plastic forming process, the deformation compatibility of welded joints was significantly improved, and its plasticity was increased by 21%.