世界上炼钢工艺,近三十年来发生了明显的变革,如氧气转炉取代平炉,连铸代替模铸,以及铁水预处理和钢水炉外精炼等工艺的采用,使平炉钢的比重逐年下降。但因各国经济和资源条件的不同,炼钢发展过程也不同。目前世界平炉钢的产量,苏联仍占60％以上,美国占11％,而日本的平炉已全部被转炉所取代。 The steelmaking process in the world has undergone significant changes in the recent three decades. For example, replacing oxygen furnace with open hearth and continuous casting instead of casting, and using hot metal pretreatment and molten steel furnace refining have led to the declining proportion of open hearth steel. However, due to the different economic and resource conditions in various countries, the process of steelmaking is also different. At present, the output of open-hearth steel in the world is still above 60% by the Soviet Union and 11% by the United States, while the open hearth in Japan has all been replaced by the converter.