Effect of process parameters in laser cladding on substrate melted areas and the substrate melted shape

摘要

In the present study, the application of fiber laser cladding by off-axis powder injection is studied as a surface treatment or coating process. The aim of this study is to analyze the effect of laser power, powder feeding rate, and cladding speed to melt the pool shape. The effects of change in process parameters on clad bead substrate melted areas are also studied. The influence of the laser beam's energy input into the melt pool is also discussed in this paper. This study is based on single pass clad layers, the additive material used was 316L stainless steel and S355 structural steel worked as the substrate material. By systematic change in the main laser cladding process parameters (cladding speed, laser power, and powder feeding rate), the process parameters' effect on the clad bead shape was studied. The process parameters were studied by using the design of experiment methodology. This multilevel full-factorial method experimentally (by use of preliminary test results) optimized the test matrix. Through statistical analysis of the results, it was observed that the laser power and powder feed rate were the main factors controlling the substrate melted area. This study successfully established the relationship between the main laser cladding process variables and the substrate melting area and substrate melted shape. The analysis concluded that low powder feeding rates and cladding speeds melt the substrate material thus increasing the dilution. However, it was also observed that in some cases there was less penetration in the side of the clad bead than in the middle. In addition, the asymmetrical substrate melted shape was observed when the powder feed rate was increased. (C) 2015 Laser Institute of America.