Acta Scientiarum Polonorum

The paper deals with the problem of determining the heating time of a bundle of flat steel bars. To describe a mathematical model of transient heat transfer the energy balance method was used. The most important element is to determine the effective thermal conductivity coefficient using the electrical analogy. The simulations of heating were performed for increasing temperature of furnace. The results show that using different sizes and bundle arrangement the heating time can be reduced by 5–15%. The analysed problem is important from the practical point of view because it allows for optimization of heat treatment processes of steel bars.