Using Response Surface Methodology (RSM) to Optimize the Key Laser Processing Parameters for Laser Cladding of Grey Cast Iron

Optimizing the key process parameters in laser repair engineering and reduce the dilution rate of the clad layer has attracted widespread attention. Based on response surface methodology (RSM) analysis the DesignExpert software was used to design a central composite laser cladding experiment with 12 axial points and 4 central points. Laser cladding of HT250 grey cast iron with Fe-based alloy powder was achieved with a high power diode laser (HPDL). The laser power, scanning speed and powder feeding rate were used as the optimization variables. The clad layer width, clad layer height, substrate melting depth and dilution rate were used as response characteristic variables. A regression prediction model of process parameters with corresponding response characteristics was established by variance analysis of test results. The process parameters were optimized by software optimizer and the accuracy of the model was verified by actual experiments. The maximum dilution rate of the clad layer under the optimal process parameters 7.296%, the average error rate of the model was within the allowable range.