Manufacturing method for slab and continuous casting equipment

A continuous casting equipment comprising:

• a twin-drum continuous casting apparatus in which a pair of cooling drums having dimples formed on surfaces of the cooling drums and a pair of side weirs form a molten metal storage portion, and that casts a slab having protrusions formed by the dimples from molten metal stored in the molten metal storage portion while the pair of cooling drums are rotated;
• a cooling apparatus that is arranged on a downstream side of the twin-drum continuous casting apparatus and cools the slab;
• an in-line mill that is arranged on a downstream side of the cooling apparatus and performs one-pass rolling on the slab with a work roll at a rolling reduction of 10% or larger;
• a coiling apparatus that is arranged on a downstream side of the in-line mill and coils the slab into a coil;
• a measurement apparatus that actually measures a rolling load and a forward slip of the slab rolled with the in-line mill;
• and
• a lubrication control apparatus configured to:
• calculate a friction coefficient from measured values of the rolling load and the forward slip using a rolling analysis model, the rolling analysis model using an Orowan theory and a deformation resistance model formula based on a Shida's approximate formula,
• calculate a difference between the friction coefficient that was calculated and a target friction coefficient having a value within a predetermined range, the predetermined range being 0.15 or more and 0.25 or less;
• calculate an adjustment amount of a lubrication condition corresponding to the difference that was calculated between the friction coefficient and the target friction coefficient;
• and
• control the lubrication condition during rolling of the slab based on the adjustment amount that was calculated.