Influence of the magnetic permeability on modeling of induction surface hardening

2017 ◽  
Vol 36 (2) ◽  
pp. 555-564 ◽  
Author(s):  
Jerzy Barglik ◽  
Albert Smalcerz
Keyword(s):  
Magnetic Permeability ◽  
Surface Hardening ◽  
Calculation Model ◽  
Temperature Fields ◽  
Hardness Distribution ◽  
Current Frequency ◽  
Content Type ◽  
Magnetic Strength ◽  
Gear Wheels ◽  
Induction Surface Hardening

Purpose Modeling of induction surface hardening strongly depends on accuracy of material properties data and their temperature characteristics. However, it is especially complicated in case of the magnetic permeability dependent not only on temperature but also on the magnetic strength. This paper aims to estimate the influence of the magnetic permeability on modeling of coupled physical fields describing the process. Investigations are provided for the gear wheels made of the steel C45E. Design/methodology/approach Computation of coupled electromagnetic temperature and hardness fields is based on FEM methods. The Flux 3D software is applied for the numerical simulation of coupled electromagnetic and temperature fields. The QT Steel software is applied for a determination of the hardness and microstructure distributions. Findings Obtained results may be used as a kind of background for the design of induction surface hardening systems. Research limitations/implications The presented calculation model provided quite a good accuracy of hardness distribution validated by the experiments. Next work in the field should be aimed at taking into account a dependence of the magnetic permeability on the field current frequency. Originality/value Mathematical model of induction surface hardening with taking into account time dependence on the magnetic permeability on temperature and magnetic strength is elaborated. Experimental validation of hardness distribution is provided. A quite reasonable convergence between simulations and measurements was achieved.

Mathematical modeling of induction surface hardening

2016 ◽  
Vol 35 (4) ◽  
pp. 1403-1417 ◽  
Author(s):  
Jerzy Barglik
Keyword(s):  
Critical Temperature ◽  
Surface Hardening ◽  
Numerical Models ◽  
Induction Hardening ◽  
Dual Frequency ◽  
Proper Selection ◽  
Content Type ◽  
Induction Surface Hardening ◽  
Selection Of ◽  
Upper Critical Temperature

Purpose – As far as the author knows the modeling of induction surface hardening is still a challenge. The purpose of this paper is to present both mathematical models of continuous and simultaneous hardening processes and exemplary results of computations and measurements. The upper critical temperature Ac3 is determined from the Time Temperature Austenization diagram for investigated steel. Design/methodology/approach – Computation of coupled electromagnetic, thermal and hardness fields is based on the finite element methods, while the hardness distribution is determined by means of experimental dependence derived from the continuous cooling temperature diagram for investigated steel. Findings – The presented results may be used as a theoretical background for design of inductor-sprayer systems in continual and simultaneous arrangements and a proper selection of their electromagnetic and thermal parameters. Research limitations/implications – The both models reached a quite good accuracy validated by the experiments. Next work in the field should be aimed at further improvement of numerical models in order to shorten the computation time. Practical implications – The results may be used for designing induction hardening systems and proper selection of field current and cooling parameters. Originality/value – Complete mathematical and numerical models for continuous and simultaneous surface induction hardening including dual frequency induction heating of gear wheels. Experimental validation of achieved results. Taking into account dependence of the upper critical temperature Ac3 on speed of heating.

scholarly journals Comparison of single and consecutive dual frequency induction surface hardening of gear wheels

2018 ◽  
Vol 355 ◽  
pp. 012015
Author(s):  
J Barglik ◽  
K Ducki ◽  
D Kukla ◽  
J Mizera ◽  
G Mrówka-Nowotnik ◽  
...  
Keyword(s):  
Surface Hardening ◽  
Dual Frequency ◽  
Gear Wheels ◽  
Induction Surface Hardening

New benchmark solutions for transient natural convection in partially porous annuli

2016 ◽  
Vol 26 (3/4) ◽  
pp. 1187-1225 ◽  
Author(s):  
Nicola Massarotti ◽  
Michela Ciccolella ◽  
Gino Cortellessa ◽  
Alessandro Mauro
Keyword(s):  
Natural Convection ◽  
Free Convection ◽  
Transient Flow ◽  
Flow Behavior ◽  
Outer Radius ◽  
Temperature Fields ◽  
Content Type ◽  
Transient Natural Convection ◽  
Velocity And Temperature Fields ◽  
Benchmark Solutions

Purpose – The purpose of this paper is to focus on the numerical analysis of transient free convection heat transfer in partially porous cylindrical domains. The authors analyze the dependence of velocity and temperature fields on the geometry, by analyzing transient flow behavior for different values of cavity aspect ratio and radii ratio; both inner and outer radius are assumed variable in order to not change the difference ro-ri. Moreover, several Darcy numbers have been considered. Design/methodology/approach – A dual time-stepping procedure based on the transient artificial compressibility version of the characteristic-based split algorithm has been adopted in order to solve the transient equations of the generalized model for heat and fluid flow through porous media. The present model has been validated against experimental data available in the scientific literature for two different problems, steady-state free convection in a porous annulus and transient natural convection in a porous cylinder, showing an excellent agreement. Findings – For vertically divided half porous cavities, with Rayleigh numbers equal to 3.4×106 for the 4:1 cavity and 3.4×105 for the 8:1 cavity, the numerical results show that transient oscillations tend to disappear in presence of cylindrical geometry, differently from what happens for rectangular one. The magnitude of this phenomenon increases with radii ratio; the porous layer also affects the stability of velocity and temperature fields, as oscillations tend to decrease in presence of a porous matrix with lower value of the Darcy number. Research limitations/implications – A proper analysis of partially porous annular cavities is fundamental for the correct estimation of Nusselt numbers, as the formulas provided for rectangular domains are not able to describe these problems. Practical implications – The proposed model represents a useful tool for the study of transient natural convection problems in porous and partially porous cylindrical and annular cavities, typical of many engineering applications. Moreover, a fully explicit scheme reduces the computational costs and ensures flexibility. Originality/value – This is the first time that a fully explicit finite element scheme is employed for the solution of transient natural convection in partially porous tall annular cavities.

Numerical calculation of crack width in prestressed concrete beams with bond-slip effect

2019 ◽  
Vol 15 (2) ◽  
pp. 523-536
Author(s):  
Jinliang Liu ◽  
Yanmin Jia ◽  
Guanhua Zhang ◽  
Jiawei Wang
Keyword(s):  
Numerical Calculation ◽  
Numerical Model ◽  
Prestressed Concrete ◽  
Calculation Method ◽  
Crack Width ◽  
Calculation Model ◽  
Content Type ◽  
Bond Slip ◽  
Stress Calculation ◽  
Bonding Performance

Purpose The calculation of the crack width is necessary for the design of prestressed concrete (PC) members. The purpose of this paper is to develop a numerical model based on the bond-slip theory to calculate the crack width in PC beams. Design/methodology/approach Stress calculation method for common reinforcement after beam crack has occurred depends on the difference in the bonding performance between prestressed reinforcement and common reinforcement. A numerical calculation model for determining the crack width in PC beams is developed based on the bond-slip theory, and verified using experimental data. The calculation values obtained by the proposed numerical model and code formulas are compared, and the applicability of the numerical model is evaluated. Findings The theoretical analysis and experimental results verified that the crack width of PC members calculated based on the bond-slip theory in this study is reasonable. Furthermore, the stress calculation method for the common reinforcement is verified. Compared with the model calculation results obtained in this study, the results obtained from code formulas are more conservative. Originality/value The numerical calculation model for crack width proposed in this study can be used by engineers as a reference for calculating the crack width in PC beams to ensure the durability of the PC member.

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