The purpose of the work is to determine rational schemes for their
production by analyzing the technological and design parameters of a number of
broadband mills that roll hot-rolled strips less than 2,0 mm thick. It is shown that at
present there is a constant increase in the production of extremely thin hot-rolled strips
(0,8-1,5 mm thick), which can be used instead of more expensive (by $ 20-30 per ton)
cold-rolled strips. The development of the production of hot-rolled strips of such a
thickness is limited by a number of problems, in particular, the low temperature of the
end of rolling (760-820 °C), which leads to a significant decrease in the ductility of the
rolled stock; limiting the rolling filling speed, which does not allow increasing the
temperature of the end of rolling the complexity of controlling the cross-sectional profile
and flatness of the strips. Using mathematical modeling, it was found that the strip
thickness and rolling speed have the greatest influence on the temperature of the end of
rolling. The thickness and temperature of the rolls at the entrance to the finishing group
of stands have a lesser effect. A decrease in the number of stands in the finishing group
increases the temperature of the end of rolling at a constant thickness of the rolls, but
when the thickness of the rolls changes in accordance with the number of stands, the
effect is significantly reduced. The most favorable technological parameters for the
production of extra-thin hot-rolled strips are provided by casting and rolling units, which
are characterized, in comparison with broad-strip mills, as a rule, by a greater thickness
and temperature of the rolls (or continuously cast slabs) and a smaller number of stands.
An increase in the thickness of billets (slabs) requires an increase in the permissible
values of the energy-power parameters of rolling, as well as the use of special solutions
that will ensure minimal heat loss by the rolls before entering the finishing group of
stands. Calculations show that, based on the reliable maximum refueling speed of hotrolled strips (10-11.5 m / s) achieved in the industry, the minimum thickness of strips with high plastic characteristics is: for broad-strip mills - 1.9-2.0 mm; for casting and
rolling units, depending on their type - 1.3-1.6 mm.
Features of technological schemes and equipment for the production of thin strips on hot strip mill
