日本新日铁发明了强弱交替吹氧炼钢法。该方法的特征是,以预先经过脱硅、脱磷、脱硫处理的铁水作为主要原料,以顶吹氧作为主要的脱碳精炼手段,在炼铁过程中,反复进行强弱交替的吹氧,使铁水表面因顶吹氧而形成的凹面深度交替的增大和减小,以促进碳的二次燃烧反应,并提高铁水的脱碳升温率。一般,氧气炼钢法的二次燃烧率在10％以下,而且燃烧热效率低,充其量为20％左右。因此近年来提出在炼钢炉内直接回收二次燃烧所产生的热量,用以提高铁水温度和熔化废钢或铁矿石等冷 Japan’s Nippon Steel invented the strength of the alternate oxygen steelmaking method. The method is characterized in that molten iron, which is desiliconized, dephosphorized and desulfurized in advance, is taken as a main raw material, and top oxygen blowing is taken as the main decarburization refining method. In the ironmaking process, So that the hot metal surface due to the top blowing oxygen formed concave depth alternately increases and decreases, in order to promote the secondary combustion of carbon and improve the rate of hot metal decarburization. In general, oxygen steelmaking secondary combustion rate of 10% or less, and low combustion heat efficiency, at best, about 20%. In recent years, therefore, it has been proposed to directly recover the heat generated by the secondary combustion in the steelmaking furnace to increase the temperature of the molten iron and to melt the cold such as scrap or iron ore