have become more widely used recently. The development devoted to the in-depth
study of strengthening processes and additional properties of the steels with carbon
content from 0.06% and below [9, 11, 16, 20, 21] has been further evolved. Of
particular interest is the study of the impact of various cooling rates on the structure
and properties of the rolled products [12, 22], when using TMCP, which demonstrates
the influence of significant increase in properties with the cooling velocity
enhancement.
The existing technologies make it possible to manufacture the rolled products with
a yield strength of up to 800 MPa and above. However, processing of materials with
new, higher levels of properties creates new challenges that need to be further explored
[13, 16].
At the same time, in addition to the development of technology and in-depth study
of its impact on new properties of the rolled products, the trend aimed at forecasting
technology implementation results through the simulation of microstructure
development and mechanical properties proposed, for instance, by the authors [7, 8]
has gained prevalence.
Among the many scientific papers, which address TMCP technology
introduction, the critical issue remains the combination of objectives with the level of
strength properties of the product mix, which must be mastered on the existing
equipment that has certain limited technical capabilities. However, optimal
combination between the chemical composition of steel, the technology potential and
the obtained strength properties of the rolled products should be taken into account in
order not to manufacture too expensive final product.
The development of TMCP technology for manufacturing hot rolling coils with a
section of 6×1500 mm (steel grade S355MC) for the rolling mill 1700, without
upgrading at this stage, is a crucial task that will enable to produce the coils from the
most common steel grade and meet the needs of the enterprise key customers.
Statement of basic materials. The existing equipment of the rolling mill 1700
currently consists of four reheating furnaces, of which three are of pusher type. The
mentioned three furnaces have been revamped to heat the slabs up to 250×1550×6200
mm. One walking-beam furnace (Stein Heurtey, France) may heat the slabs up to
250×1600×10500 mm. 250 mm thick slab is used for production only in case of
reduction at the slabbing mill. The roughing train includes one two-high stand No. 01
(roughing scale breaker) and 5 four-high stands (1-4, and 4a), of which four are
universal ones (2-4, and 4a). There are also installed heat-saving shields, rotary shears.
The finishing train includes 6 four-high stands (5-10), accelerated cooling unit, which
in turn consists of 14 sections and 3 coils, of which two may wind the coils weighing
up to 9 tonnes, and one, the latter in the rolling direction, may wind the coils weighing
up to 27 tonnes. It is worth noting that 7 descalers with a pressure of 80-140 atm are
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