Open AccessFeatures of technological schemes and equipment for the production of thin strips on hot strip mill
Author(s) -
S. A. Vorobei,
I. Yu. Prykhodko,
V. V. Raznosilin
Publication year - 2020
Publication title -
fundamentalʹnye i prikladnye problemy černoj metallurgii/fundamental and applied problems of ferrous metallurgy
Language(s) - English
Resource type - Journals
eISSN - 2786-6149
pISSN - 2522-9117
DOI - 10.52150/2522-9117-2020-34-159-169
Subject(s) - strips , flatness (cosmology) , hot rolled , limiting , mill , materials science , rolling mill , metallurgy , composite material , mechanical engineering , engineering , physics , cosmology , quantum mechanics
The purpose of the work is to determine rational schemes for theirproduction by analyzing the technological and design parameters of a number ofbroadband mills that roll hot-rolled strips less than 2,0 mm thick. It is shown that atpresent 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 athickness is limited by a number of problems, in particular, the low temperature of theend of rolling (760-820 °C), which leads to a significant decrease in the ductility of therolled stock; limiting the rolling filling speed, which does not allow increasing thetemperature of the end of rolling the complexity of controlling the cross-sectional profileand flatness of the strips. Using mathematical modeling, it was found that the stripthickness and rolling speed have the greatest influence on the temperature of the end ofrolling. The thickness and temperature of the rolls at the entrance to the finishing groupof stands have a lesser effect. A decrease in the number of stands in the finishing groupincreases the temperature of the end of rolling at a constant thickness of the rolls, butwhen the thickness of the rolls changes in accordance with the number of stands, theeffect is significantly reduced. The most favorable technological parameters for theproduction of extra-thin hot-rolled strips are provided by casting and rolling units, whichare characterized, in comparison with broad-strip mills, as a rule, by a greater thicknessand 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 permissiblevalues of the energy-power parameters of rolling, as well as the use of special solutionsthat will ensure minimal heat loss by the rolls before entering the finishing group ofstands. 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 androlling units, depending on their type - 1.3-1.6 mm.