Comparative study of continuous and pulsed laser high-chromium steel (Fe-Cr-Ni-Mo-Mn) cladding

Abstract

Series of experiments of high chromium steel (Fe-Cr- Ni-Mo-Mn) laser cladding over a 316L substrate have been carried out in both pulsed and continuous modes, using an Yb-YAG disk laser.The investigation focused on the effects of cladding parameters such as laser pulse energy, duration and travel speed, on cladding properties including dimensions, microstructure and hardness.The different claddings obtained in this study were characterized in terms of microstructural changes, phase composition, and carbide distribution and morphology using Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS).Also, the size and the orientation of the grains in the clad after rapid solidification have been observed by electron backscattered diffraction (EBSD). It was observed that the use of pulsed laser resulted in finer microstructure and higher hardness.Wear tests were performed using pin-on-disk device under argon to prevent sample oxidation, at room temperature for pulsed and continuous laser power. Different wear mechanisms were observed, with pulsed laser cladding and high duty cycle exhibiting better wear resistant. Indeed, the lowest average friction coefficient is obtained with pulsed laser and is relatively stable with the change in sliding time.The relationship between the scale of the dendritic network and the corresponding wear behavior has been discussed.Series of experiments of high chromium steel (Fe-Cr- Ni-Mo-Mn) laser cladding over a 316L substrate have been carried out in both pulsed and continuous modes, using an Yb-YAG disk laser.The investigation focused on the effects of cladding parameters such as laser pulse energy, duration and travel speed, on cladding properties including dimensions, microstructure and hardness.The different claddings obtained in this study were characterized in terms of microstructural changes, phase composition, and carbide distribution and morphology using Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS).Also, the size and the orientation of the grains in the clad after rapid solidification have been observed by electron backscattered diffraction (EBSD). It was observed that the use of pulsed laser resulted in finer microstructure and higher hardness.Wear tests were performed using pin-on-disk device under argon to prevent sample oxidation, at room temperature for pulsed...