A Numerical Analysis Approach to Evaluate Hardness and Distortion for Selected Multi-Track Laser Cladding Configurations: P420 Steel Bead Deposition on Mild Steel

Laser cladding is a surface modification technique that is being explored as an additive manufacturing solution for metal. The laser cladding process is associated with nonuniform material strength within the clad and the heat-affected-zone. In addition, residual stress development increases the crack driving forces and reduces the fatigue life of the part. In the present work, a 3D transient fully coupled thermal-metallurgical-mechanical numerical model was built to simulate the coaxial powder injection laser cladding process for P420 stainless steel powder on an AISI 1018 steel plate for 50% +/− 10% bead overlap conditions. This work is an extension of prior physical and virtual simulation analyses. The model was employed to explore the effect of depositing directions and overlapping configurations on the temperature field evolution, thermal cycling characteristics, mechanical properties, and induced distortions in the clad and substrate. The model was validated by Vickers microhardness measurements and heat-affected-zone geometry from the specimens’ cross-sectioning. The simulation results show good agreement with experimental measurements with a 14% maximum error. It was found that the 50% bead overlap configuration with a raster fill deposition pattern had the most consistent hardness results, and minimal distortion. The presented simulation methodology can be used to predict the mechanical and physical properties of laser cladded components and to provide relevant information for process planning decisions.