Magnitogorsk Iron & Steel Works (Magnitogorsk, Russia):

Prokhorov S. V., Chief Metallurgist
Kazakov A. S., Leading Specialist,  kazakov.as@mmk.ru
Yurechko D. V., Head of Laboratory
Moshkunov V. V., Engineer Technologist
Kulzhov A. A., Foreman of Continuous Caster

The paper is devoted to investigation of precision of continuously cast slabs. It was found out that steel casting without varying of mold width, i.e. with conservation of initial position of narrow walls relating to the mold axis, can't provide manufacturing of slabs with preset width, even with maximal allowing deviation ±1%. During examination of this problem, it was established that speed of dillet pulling out of the mold and chemical composition of cast steel has effect on billet widening: the more is pulling speed, the more becomes width. In order to receive slab billet without excessive width deviation from its nominal value, correcting coefficients characterizing relationship between billet widening and billet pulling speed, have been included in the software. As a result, concrete parameters for decrease of mold width required for manufacturing of 2,600 mm wide billets made of 10G2FBYu and 15KhSND steels are recommended. Practical measurements of actual slab width after their cooling down to room temperature have been conducted for checking of introduced changes; these measurements have been done on upper slab plane, on the distance 150 mm from edges and along slab center. Therefore, it was concluded that production of continuously cast slabs with narrow allowed width deviation, using continuous casters with large height of mold location above the horizontal unit section, should be accompanied by dynamic mold adjusting, taking into account widening ratio.