Development of Mould Powder for High Speed Continuous Casting of Medium Carbon Steel Slab

摘要

Mold powder as an important supplemental material for continuous casting influences slab quality directly, and more strict requirements are necessary for the continuous casting of medium carbon steel duo to its solidification characters. The present work studied the effect of composition on properties of mould powder and developed a series of mould powder products for continuous casting of medium carbon steel. The results showed that both crystallization and breaking temperatures as well as grain size in the solidified flux film were all deceased by adding some special component such as B2O3, Li2O, MnO. Consequently, by preventing deposit of high melting phases during cooling process, liquid flux film on the surface of solidified shell was formed to insure the greasing performance, and at the same time, the crystallized flux film was formed on the side of mould wall to maintain uniform weak heat transfer. Practical application of the developed serious mold powder products showed good performance and the slab quality was effectively improved for continuous casting of medium carbon steel.