Simulation Of Electromagnetic Induction Quenching Of Crankshaft And Study On Prediction Method Of Fatigue Property

As one of the important parts of the engine,the crankshaft is subjected to loads from various aspects during operation,and the stress concentration on the oil hole and the transition fillet often causes the crankshaft to break.How to predict the fatigue strength limit of the crankshaft precisly after induction hardening at the beginning of the design stage is the original intention of this study.In this paper,based on the electromagnetic induction quenching technology and its basic theory,the finite element analysis method is used to simulate the electromagnetic induction surface quenching process of the crankshaft connecting rod journal and transition fillet of a domestic diesel engine.The uniaxial stress and the multiaxial stress-strain state are considered respectively,the Goodman’s modified formula is used to predict the fatigue limit load of the crankshaft after induction hardening and test verification.This paper takes a domestic diesel engine crankshaft as the research object,and focuses on the two aspects of the crankshaft electromagnetic induction quenching simulation and fatigue property prediction method.The main research contents include:(1)Using Altair Flux electromagnetic thermal coupling simulation software to simulate the electromagnetic induction surface quenching heating process at the crankshaft connecting rod journal and transition fillet,the electromagnetic field and temperature field at the crankshaft connecting rod journal and transition fillet are calculated.(2)In the process of cooling fluid cooling simulation,the applied load is the temperature field at the end of quenching heating,and the temperature field in the rapid cooling stage of the cooling fluid is obtained by simulation.(3)The thermal coupling finite element software ABAQUS is used to simulate the long-term cooling process in the air and the residual stress field remaining in the crankshaft after air cooling.The temperature field at the end of the cooling liquid cooling is used as the initial load to obtain the temperature field of the crankshaft cooling in the air for a long time,and then the temperature field of the entire air cooling process is used as the load to calculate the residual stress field.(4)Consider the uniaxial stress-strain state and the multiaxial stress-strain state respectively,and use Goodman’s correction formula to predict the fatigue limit load of the crankshaft after induction hardening.After experimental verification,the multi-axis fatigue model based on the critical plane method is combined Goodman’s formula can accurately predict the fatigue limit load of the crankshaft after induction hardening.