Development of Direct Rolling Technology at Hot Rolling Mills

摘要

Nippon Steel first began hot direct rolling (hereinafter referred to as "HDR") at Nagoya Works in December 1973, and at Sakai Works in January 1974. At Nagoya Works, the concept of HDR was formulated in 1958 when the construction of the hot strip mill was in the planning stage. As a result of the oil crisis in the fall of 1973, HDR was promoted as an important energy saving technique.Although a fairly large percentage of products are now produced by HDR at both works, the tendency toward the continuous casting of slabs has changed the trend of technology. First, we shall discuss problems related to the HDR process and their countermeasures and next we shall show the results of HDR operation at Nippon Steel. Finally we shall examine the prospects of related future technology.