High Carbon Strip Producing Technology On Thin Slab Casting Direct Rolling Process In Zhujiang Steel

摘要

Thin slab casting and direct rolling process (hereinafter referred to as "TSCR"), characterized by high liquid steel solidification rate, low heating temperature and short stay time in the roller-hearth furnace, high pass reduction, helps to inhibit the segregation of chemical composition, refine the nonmetallic inclusions, lower surface decarburization, reduce the inter-laminar distance of pearlite, and consequently, to some extent alleviates the problems that traditional production process has in producing high-carbon strips. TSCR is a suitable process for producing high-quality high-carbon strips, as its maximum carbon segregation rate is 1.16, much lower than 2.0 of traditional process, its single face decarburization depth is less than 1.0% of strip's thickness, only 30-60% of that of traditional process, its pearlite inter-laminar distance is much smaller than that of traditional process, which are favorable for increasing the overall performance of the materials. The application of special cover powder with melting point (HT) 840-960°C, viscosity 0.800.83 poise (at 1300°C), and alkalinity 0.85 to 0.92 will result in stable casting of high carbon steel (with carbon content 0.65-1.0% ) on TSCR's caster, with breakout rate < 0.2%, longitudinal crack rate < 0.1%. Zhujiang steel, on its TSCR process, has developed and mass produced high carbon tool steels like T7, T8, T10, SK85, SK4, SK5, M100 and alloy tool steels 75Cr1, 8CrV2, SKS51, with carbon content up to 1.0%, thus broadening the products variety of TSCR, these products have been widely used in industries like automotive manufacturing, engineering machinery, special equipment, high-end blade and special tools.