Current Status of Continuous Casting Technology and Quality

With reference to the rapid increase in the use of continuous casting in Japanese steel mills since the early 1970s, current technology is reviewed in this field, concentrating on thin plate slab continuous casting (the technology which has been responsible for the fact that over 90% of Japanese steel mills now have continuous casting), quality aspects of continuous cast materials, and future trends. Technology which has increased productivity in continuous casting is stated to be support equipment for use directly underneath cast material, high-speed casting powder, and techniques to prevent reduction in quality of cast material. Improvements in time efficiency in the continuous casting process are stated to be multiple casting techniques, shortening of preparation time, and general reduction in handling time due to greater automation. For the future of continuous casting, the CC--DR method, developed by Shin-Nippon Steel, is stated to have considerable advantages in that it provides for maximum energy saving and shortens handling time. Nippon Kokan has achieved 2.5 m /min. at one of its mills with this method. The other method concluded to have the greatest advantages for the future is the "near net shape" method introduced into Japan about three years ago on a large scale. 47 ref.--J.G.