EFFECT OF SOAKING TEMPERATURE AND ANNEALING ATMOSPHERE ON MAGNETIC-PROPERTIES OF SEMI-PROCESSED NONORIENTED ELECTRICAL STEEL CONTAINING 0.4-PERCENT SILICON

In order to investigate the effect of soaking temperature and annealin g atmosphere on magnetic properties of the semi-processed nonoriented electrical steel containing 0.4 % silicon, customer annealing was carr ied out at a temperature ranging from 730 to 950 and in different anne aling atmospheres. As the soaking temperature increases from 730 to 95 0 in the dry N2 atmosphere, the core loss at 1.5 Tesla decreases conti nuously, whereas the permeability at 1.5 Tesla increases up to 890 and then decreases significantly at 950 degrees C. Among DX atmospheres h aving a dew point of -23 degrees C, the air to LPG ratio of 19.5 is fo und to reveal the best magnetic properties due to the lowest carbon co ntent. At a dew point of +5 degrees C and an air to LPG ratio of 18.5 the best magnetic properties are to be achieved regarding both carbon content and internal oxidation layer.