前言近二十年来,电炉(AF)钢的产量和质量都有了很大的提高。一方面是由于变压器容量的超高功率化(UHP),另一方面是由于二次精炼,即炉外精炼的发展。直到六十年代中期,钢的精炼只限于炉内完成,而钢包只是作为出钢的容器。然而,二次精炼工艺则改变了钢包的作用,使其成为精炼设备,并使钢的精炼不在电炉内,而在电炉外进行。这一改进主要是由于下列原因: Preface The output and quality of electric furnace (AF) steels have been greatly improved over the past two decades. On the one hand due to the ultra high power transformer capacity (UHP), on the other hand due to the secondary refining, that is, the development of furnace refining. Until the mid-1960s, the refining of steel was done only in the furnace, and the ladle was only used as a tapping container. However, the secondary refining process changed the role of the ladle to make it a refining equipment and the refining of the steel was not carried out in the electric furnace but outside the electric furnace. This improvement is mainly due to the following reasons: