Experimental results show that heat-and mass-transfer processes in recirculating turbulent flows, which comprise several vortexes of the mean flow, are significantly influenced by low-frequency large scale flow oscillations. The large eddy simulation (LES) model reproduces with good conformity not only these oscillations together with the dynamics of the macroscopic coherent structure, but also the turbulent energy transfer. Numerical studies, presented in this article, confirm the possibility of using LES for successful simulation of heat-and mass-transfer processes in metallurgical applications.

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Despite the ongoing debates on influence of hydrogen uptake and penetration in the steel, pulsed and extraordinary fatigue on white etching cracks (WEC) formation in bearing steel SAE52100, the present paper proposes an alternative hypothesis on electrothermal initiation of the WEC. The hypothesis points to differences between electrical and thermal properties of elements of steel microstructure that lead sequentially to redistribution of current, resistivity heating, thermal expansion and deformations of the carbide particle. Appearance of a nano-void is also predicted by the model in the cases of the martensite and the bainite structures. The model also predicts higher probability of the WEC formation for the bainitic steel.

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