Simulation Methodology to Analyze Overall Induction Heat Treatment Process of a Crank Shaft to Determine Effects on Structural Performance 2020-01-0506
Steel crankshaft are subjected to an induction heat treatment process for improving the operational life. Hence, to predict the structural performance of a crankshaft using Computer Aided Engineering early in the design phase, it’s very important to simulate the overall induction heat treatment process. Metallurgical phase transformations during the heat treatment process have direct influence on the hardness and residual stress. The objective of this study is to establish the overall analysis procedure, starting from capturing the eddy current generation in the crank shaft due to rotating inductor coils to the prediction of resultant hardness and the induced residual stress. In the proposed methodology, an electromagnetic analysis is performed first to capture the Joule heating due to the surrounding inductor coil carrying high frequency alternating current. Then coupling is done between the electromagnetic and thermal analysis to capture the resultant temperature distribution due to the rotation of the inductor coil by a novel approach. Subsequent quenching operation is simulated then to capture the metallurgical phase changes and hardness using a python subroutine based on continuous cooling transformation (CCT) diagram. In this paper, circumferential temperature distribution of the crankshaft is presented at the end of induction heating process. The metallurgical phase distributions and its consequences on hardness is also explained in this paper. Currently, this methodology is able to predict the residual stress due to thermal gradient only. Residual stress developed due to microstructural changes is not being considered in this study. The simulation methodology explained in this study to analyze the overall induction heat treatment process can be implemented to create robust designs during initial design phases of crankshafts.
Nilankan Karmakar, Anoop Retheesh, Pankaj Kumar Jha, Michael D. Nienhuis