New economically effective steel strips production technologies (based on materials of international conferences)

Production of steel rolled products by using traditional metallurgical technologies are rather material- and energyintensive and its concentration at gigantic steel plants resulted in the increased expenses for transportation of raw materials and finished products. To solve the problems, a practice of comparatively small metallurgical plants (mini-mills) construction is becoming widespread in the world steel industry. The mini-mills include modern electric arc furnaces, ladle steel treatment facilities and steel continuous casters combined with continuous rolling mills. The review complied from materials of international conferences, taken place in 2015–2019. In the review achievements in equipment and technology of metal products at mini-mills development considered, as well as analysis of modern economical methods of steel coils presented. It was shown, that the methods of strips endless rolling, widely used already at industrial scale in several countries, enable producing rather thin hot-rolled strips from liquid steel. Universal casting-rolling aggregates (CRA) developed, by which high quality strips of rather wide assortment can be produced. For a mass production of rather thin (down to 0.8 mm) hot-rolled strips, which can in many applications substitute more expensive coldrolled ones, compact aggregates of endless casting-rolling are recommended, which provide the yield of up to 98%. Concepts of the CRA elaborated for production of steel strips of wide assortment, from ultrathin strips to thick (25 mm) ones. The concepts include application of thermomechanical treatment to increase the mechanical properties of the rolled products from various steels, including low-alloyed ones.