Integrated Numerical and Taguchi-Based Optimisation of Forging Parameters for DIN 42CrMo4 Engine Connecting Rod Steel

This article reports on the optimisation of forging process parameters using Deform 3D simulation software and Taguchi methodology. The process parameters considered were temperature, die velocity, and temperature and friction coefficient. The workpiece material was 42CrMo4 steel used to manufacture the engine connecting rod. The output responses were maximum stress, maximum strain, maximum tensile stress and damage. The simulation design had three levels for each process parameter. The study used Taguchi L9 orthogonal array. Taguchi's analysis gave two sets of optimal conditions. Case 1: temperature (1200°C), die velocity (100 mm/s), die temperature (250°C) and friction coefficient (0.2) from S/N ratios analysis. Case 2: temperature (1200°C), die velocity (115 mm/s), die temperature (215°C) and the friction coefficient (0.2) for multiple response prediction. The ANOVA results indicate that the most significant factors were deformation temperature (influencing maximum stress and tensile stress) and friction coefficient (influencing maximum strain and damage). The die temperature and velocity had a minimal effect on the output responses. The confirmation test results show slight variation in output responses when using the two cases of optimal conditions for the predictive regression and simulation model. However, maximum tensile stress had a higher percentage error. The error results were 10.895% (Case 1) and 18.512% (Case 2). An industrial forging simulation of an engine connecting rod validated the optimal conditions. This study showed that numerical simulation and Taguchi methodology can effectively and efficiently optimize the forging process. The approach provides the basis for future industrial analyses and optimisation.