%0 Journal Article %T Numerical Investigation of Laser Surface Hardening of AISI 4340 Using 3D FEM Model for Thermal Analysis of Different Laser Scanning Patterns %A Baha Tarchoun %A Abderrazak El Ouafi %A Ahmed Chebak %J Modeling and Numerical Simulation of Material Science %P 31-54 %@ 2164-5353 %D 2020 %I Scientific Research Publishing %R 10.4236/mnsms.2020.103003 %X Laser surface hardening is becoming one of the most successful heat treatment processes for improving wear and fatigue properties of steel parts. In this process, the heating system parameters and the material properties have important effects on the achieved hardened surface characteristics. The control of these variables using predictive modeling strategies leads to the desired surface properties without following the fastidious trial and error method. However, when the dimensions of the surface to be treated are larger than the cross section of the laser beam, various laser scanning patterns can be used. Due to their effects on the hardened surface properties, the attributes of the selected scanning patterns become significant variables in the process. This paper presents numerical and experimental investigations of four scanning patterns for laser surface hardening of AISI 4340 steel. The investigations are based on exhaustive modelling and simulation efforts carried out using a 3D finite element thermal analysis and structured experimental study according to Taguchi method. The temperature distribution and the hardness profile attributes are used to evaluate the effects of heating parameters and patterns design parameters on the hardened surface characteristics. This is very useful for integrating the scanning patternsกฏ features in an efficient predictive modeling approach. A structured experimental design combined to improved statistical analysis tools is used to assess the 3D model performance. The experiments are performed on a 3 kW Nd:Yag laser system. The modeling results exhibit a great agreement between the predicted and measured values for the hardened surface characteristics. The model evaluation %K Laser Surface Hardening %K 3D Thermal Analysis %K Finite Element Modelling %K AISI 4340 Steel %K Laser Scanning Patterns %K Taguchi Method %K ANOVA %K Nd:Yag Laser Source %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=101551