1.引言日本钢铁工业一直在研究直接应用连铸扁坯、方坯技术,以期达到节约能源、改善质量之目的。采用连铸坯直接生产产品的范围正在不断扩大。产品范围包括薄板、中厚板、钢轨和型钢。由于现在最流行的斜轨穿孔对管坯要求严格,因此,管坯必须要有很高的质量。因而直接用连铸方坯就被局限在几个钢级和规格上。日本新日铁为了显著降低原料成本、改善产品质量,对中等口径无缝管生产工艺进 1. Introduction Japan’s steel industry has been studying the direct application of continuous casting of slab, billet technology, with a view to achieving energy conservation and quality improvement purposes. The scope of direct production of products using continuous casting billet is constantly expanding. The product range includes sheets, plates, rails and sections. As the most popular ramp perforation of the tube on the strict requirements, therefore, the tube must have a high quality. Therefore, the direct use of continuous casting billet is limited to a few steel grades and specifications. Japan’s Nippon Steel in order to significantly reduce the cost of raw materials, improve product quality, medium-sized seamless pipe production process into