A. Smalcerz

3D modeling of induction hardening of gear wheels

Induction hardening of gear wheels is modeled. The model consists of two nonlinear partial differential equations describing the distributions of magnetic and temperature fields in the system. All material parameters are supposed to be functions of temperature. The model is then solved numerically in the 3D hard-coupled formulation using the professional code FLUX3D supplemented with a number of own scripts and procedures. The methodology is illustrated with a typical example whose results are discussed.

Influence of the magnetic permeability on modeling of 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.

The Properties of ZnAlMg Alloys for Batch Hot Dip Metallization

In the paper the melting point of Zn-Al alloys with the addition of Mg has been determined, based on solidification curves. The alloys used for the tests were alloys containing 7, 15, 23 and 31 wt.% Al with the addition of 3 or 6 wt.% Mg. It has been determined that the solidification temperature of the ZnAlMg alloy is a synergistic effect of the Al and Mg contents. In alloys with lower contents of Al (7, 15 wt.% Al) an increase in the content of Mg leads to an increase of the melting point. In baths with higher contents of Al (23, 31 wt.% Al) the addition of Mg causes a decrease of the melting point. It has been determined that the melting point of the Zn-31Al6Mg alloy drops to 438°C, due to which the alloy can be used for metallization in temperature conditions close to the temperature of traditional hot dip galvanizing.