Modelling of temperature dependence of saturation magnetisa-tion of silicon-iron steels

The temperature dependence of saturation magnetisation of commercial 0.1 to 3 wt. % silicon steels is first measured using an air-cored solenoid and then modelled using a linear formula in accordance with the spin-wave theory, over the range of 20-100°C and in 100 KA/m applied field. The samples measured were heated by applying a heavy ac current along their length, and the measurement of temperature was made using thermocouples. The paper discusses the effect of temperature variation on magnetisation in high field regime approaching saturation in several grades of electrical steel.