Microstructure features of stainless steel after laser surface remelting and solidification

The microstructure features of stainless steel have changed remarkably after laser surface remelting and solidification. Light band, fine cell, cell-dendrite structure and disordered dendrite are found in the surface layer, meanwhile, the causes for their formation have been analyzed. The typical cell-to-dendrite transition is observed at the center of laser melt pool, and a detailed investigation on the transition conditions shows that the critical transition velocity determined by experiment agrees well with the prediction of recent BJT model.