1,720,972 research outputs found
Multiphysyical Finite Element Simulation of Contour Induction Hardening of Gears
Full text linkInduction heating has been widely applied in the field of heat treatment of components for the automotive and aerospace sectors, in particular for the hardening of a huge variety of applications. The main advantages of using this technology counts the high level of repeatability achievable in the treated product, together with the high velocity and automation of treatment, factors both able to ensure production efficiency and reduced environmental impact.
Nowadays, numerical methods are becoming more and more important as a reference method of analysis, in order to optimize the main parameters of the process, also thanks to the possibility of coupling different physical between them, a result which until a few years ago would not have been possible.
The aim of this work is the analysis and numerical modeling of the process of induction hardening of gear wheels for the aerospace industry.
In this thesis it will be shown how, starting from the electromagnetic and thermal coupled models, already extensively used in the last years by both the research and the industrial sectors, it is possible to calculate the phase transformations that occur in the steel during the heating and cooling stages.
The algorithm developed will be firstly applied on the case of a simple 2D geometry, and then the complexity level will be gradually increased (both from computational and process point of view), applying the algorithm to an induction hardening process of a gear. The numerical results thus obtained will be verified experimentally
Multiphysical-Multiscale FEM Simulation of Contour Induction Hardening on Aeronautical Gears
No full textSince many years, induction hardening has been successfully applied for the heat treatment of components, mainly in the aeronautical and automotive sectors, because of its peculiar advantages like high quality and repeatability of process and its easy automation. A multi-scale multiphysical finite element (FE) analysis is presented in this paper for the prediction of microstructural evolution during induction hardening processes. An ad hoc code has been developed in order to calculate the metallurgical phase changes that occur during heating and cooling steps. This routine has been coupled with commercial FEM codes able to solve the coupled electromagnetic and thermal problem that typically describes the induction heating processes. During the heating, the magnetic field generated by the coil induces currents in the workpiece and as consequence the heating of conductive material by Joule effect. In induction hardening of steels, an external layer of the piece is heated up to the austenitization temperature, then it is cooled down to obtain a layer of martensite. In thermo-metallurgical model, material properties depend on the temperature distribution but also on the microstructure since the material is a mixture of different phases. From the solution of the coupled steady-state, at a given frequency, electromagnetic and transient thermal problem, temperature distribution as well as heating and cooling rates are used for the evaluation of the existing metallurgical phases at every time step. The effect of latent heat of solid-solid phase transformations has been also considered. The model developed has been applied on a real complex case, e.g. an aeronautical spur gear, in order to predict the phase transformation during the whole process. The numerical results will be verified through experimental validation
Numerical FEM Simulation of Induction Hardening Process: A Multiphysical Approach
No full textInduction hardening has been widely applied for the heat treatment of components mainly in the wind-power and automotive sectors, because of its peculiar advantages like high quality and repeatability of process and its easy automation. The main purpose of these treatments, as well as increases the surface hardness of the piece, is to induce compressive residual stresses in the superficial layer, improving the fatigue behavior.
A multi-scale multiphysical finite element (FE) analysis is presented in this paper for the prediction of microstructural evolution during induction hardening processes. An ad hoc external routine has been developed in order to calculate the phase changes during heating and cooling process associated with non-isothermal transformations. This routine has been coupled with commercial FEM codes able to solve the coupled electromagnetic and thermal problem that typically describes the induction heating processes. During the heating, the magnetic field generated by the coil induces currents in the workpiece and as consequence the heating of conductive material by Joule effect.
Material properties depend on the temperature distribution but also on the microstructure since the material could be seen as a mixture of different phases, each one with different physical properties. The effect of latent heat of solid-solid phase transformations has been also considered.
From the solution of the coupled steady-state, at a given frequency, electromagnetic and transient thermal problem, temperature distribution as well as heating and cooling rates are used for the evaluation of the existing metallurgical phases at every time step
A magneto-thermo-metallurgical finite element model applied to induction hardening processes
Full text linkInduction hardening has been widely applied for the heat treatment of components mainly in the aeronautical and automotive sectors because of its peculiar advantages like high quality and repeatability of process and its easy automation. A multi-scale multiphysical finite element (FE) analysis is presented in this paper for the prediction of microstructural evolution during induction hardening processes. An ad hoc external routine has been developed in order to calculate the phase changes during heating and cooling process associated with nonisothermal transformations. This routine has been coupled with commercial FEM codes able to solve the coupled electromagnetic and thermal problem that typically describes the induction heating processes. During the heating, the magnetic field generated by the coil induces currents in the workpiece and as consequence the heating of conductive material by Joule effect. Material properties depend on the temperature distribution but also on the microstructure since the material could be seen as a mixture of different phases, each one with different physical properties. The effect of latent heat of solid-solid phase transformations has been also considered. From the solution of the coupled steady-state, at a given frequency, electromagnetic and transient thermal problem, temperature distribution as well as heating and cooling rates are used for the evaluation of the existing metallurgical phases at every time step
Numerical Simulation of Solid-Solid Phase Transformations During Induction Hardening Process
No full textA multi-scale multiphysical finite element (FE) analysis is presented in this paper to predict the microstructural evolution during
induction hardening processes. An ad-hoc code has been developed in order to calculate the metallurgical phase changes that occur
during heating and cooling steps. This routine has been coupled with a FEM code able to solve the coupled electromagnetic and thermal
problem that typically describes the induction heating processes. In induction contour hardening of steels, an external layer of the piece
is heated up to the austenitization temperature and then it is cooled down to obtain a layer of martensite. In thermo-metallurgical model,
material properties depend on the temperature distribution but also on the microstructure since the material is a mixture of different
phases. From the solution of the coupled steady-state, at a given frequency, electromagnetic and transient thermal problem, temperature
distribution as well as heating and cooling rates are used for the evaluation of the existing metallurgical phases at every time step. The
effect of the latent heat of solid-solid phase transformations has been also considered. The numerical results are compared with
experimental one
SIMULAZIONE NUMERICA DI PROCESSI DI TEMPRA AD INDUZIONE SU COMPONENTI PER L’INDUSTRIA AERONAUTICA
No full textMultiphysics FEM Simulation of Contour Induction Hardening Process on Aeronautical Gears
No full textInduction heating has been widely used by the heat treatment industry mainly in the wind-power and automotive sectors, in particular for hardening purposes, in a broad range of applications, its main advantages being the high repeatability and easy automation of the process, both factors leading to improved manufacturing efficiency and reduced CO2 emissions. Though, traditional furnace-based case hardening treatments still represent the choice of reference when performance requirements are particularly demanding, either for the critical operating conditions or safety-related issues. The processes of CIH (Contour Induction Hardening), compared to the traditional carburizing processes, allows to reduce the deformations after heat treatment. The main purpose of these treatments, as well as increases the surface hardness of the piece, is to induce compressive stresses in the superficial layer, improving the fatigue behavior.
A multiphysics magneto-thermal simulation can be developed in order to calculate the temperature distribution in the gear, setting the input parameters such as currents, frequencies and treatment time
LEP-Laboratory for Electroheat of Padua University
No full textThe Laboratory for Electroheat of Padua
University, LEP, is the only Italian academic group that researches about electroheating. LEP was founded about 40
years ago by prof. Di Pieri, it was leaded
for many years by prof. Lupi and now it is
directed by prof. Dughiero. Actually, about
10 people are working in the group. It is
also the organizer of the conference ‘HES’,
Heating by Electromagnetic Sources,
whose 6th triannual edition will take place
this year in May.
In the paper, the latest research activities
of LEP are presented, mostly with reference
to the fields where LEP concentrates its
research activity: innovative technologies for
the through heating of non ferrous billets,
contour induction hardening, silicon melting
and crystallization, microwave heating and
biomedical application of electromagnetic
fields
- …
