DonNTU   Masters' portal

Abstract

Summary on the theme of master's work

Introduction

Production of flat products in modern conditions is considered progressive, when the leaves are rolled from continuously cast slabs. For rolling of sheet width required to mix a large number of kinds of slabs are different in width, length and thickness. For slabs of different thickness and width is needed to change the molds for casting, which is difficult and involves, in addition, the need to move to a new technology and mode of filling and cooling of the metal. Establishing optimum casting speed and the cooling zvzano usually with some inevitable and malfunctions, which will eventually affect the quality of the metal. For these and other reasons it is necessary to have the ability to change the width of the slab, in particular to reduce by transverse strain in the vertical rolls. The unification of the width of the slab vimogae use of high crimp width is reduced, when in vertical rolls. This leads to the fact that most of the crimped metal passes into the influx side edge of roll and big reels also formed with ends peals or "fish tails" are trimmings in reaching 1.5 - 2%.

The main objective of reducing the width of the cut-nepererivnolitih slabs to the required sizes.

1. Theme urgency

This work is relevant, because it obtained in this study experimental models are needed for the development of mathematical models, which will be the basis of mathematical technology for the control system pressure reduction.

2. Goal and tasks of the research

In this paper the influence of compression in the vertical-horizontal rolls on the effectiveness of reducing the width of the slab is reduced, when.

The main objectives of the study:

  1. To investigate the effectiveness of reducing slab modes in the universal reversing stand for a few passes with constant and variable in length crimp.
  2. Determination of crimp reduction in slabs which provide the end rectangular peals after roughing rolling stands.
  3. The object of study: the process of changing the shape in terms of roll in rolling in the roughing stand SHSGP.

3. Overview of Research and Development

The reduction of the slab 200-300mm in the first roughing mill stands broadband is widespread in the world, as it allows all sort of a cop broad bands across the width of the receiving continuously cast slabs several widths and reduce the number of molds for casting them.

Circuit breakdowns in and HB universal roughing mill

→passages from a work by compression; --->idle pass; 50.0-away from the stove, 3.0 - distance between VS and HS

Figure 1 – Circuit breakdowns in VS and HS universal roughing mill

The nature of the distribution of breakdowns in the aisles of explosives depends the efficiency of the reduction.

The study carried out by mathematical modeling using the software package "Universal", developed in Doniks and Donetsk National Technical University. The samples selected slab thickness 240 mm width 1200 1800 mm and a length of 10 m. Modeler these samples was carried out in a universal mill. BB bowling diameter 1350 mm, horizontal - 1400 mm. The depth of the stream caliber BB 150 mm, release 0.4. The total reduction in the BB was equal to 225 mm. Reduction δВв in the aisles installed in three modes: I - with the increase, II - c reduction and III-identical. Determined width after IV (B), after GW in every forward progression (δВвg) and the total after the third pass (δВsum).

Table 1 – The results of experimental studies

Bs,mm№mode.№passageΔВv,mmΔН, mm Вv, mmВh, mm δВvh, mm δВsum,mm η ηsum М0,kgsPe,kw h/t
1216 I 150141166118115   0,7      
275  1106              
31004110061045391710,780,761381,8
II 1100261116114630   0,7      
275  1071              
3502910211053321630,750,736571,8
III 175201141116423   0,69      
275  1089              
3753510141049351670,770,744231,8
1824 I 150111774179117   0,66      
275  1716              
31002616161657411670,770,746771,3
II 1100181724175733   0,67      
275  1682              
3501916321666341580,730,714191,4
III 175141749174425   0,67      
275  1699              
3752216241662381620,750,7211181,4

According to the data obtained by experiment, it can be said that the effectiveness of reducing the width of the first passage (η) for reducing narrow slabs is higher than wide, but depends on the amount of reduction (mode number). Effectiveness in the last two pass and three pass (ηsum) above in I with prolonged compressions and cut-narrow slab is higher than wide. The value of end trim is also minimal mode with increasing compressions along the aisles and significantly lower (two to four times) with a cut-narrow slab.

Conclusion

On the basis of this data it can be said that the results were obtained To a 2-3 passages are typically used for reducing (with a considerable reduction of width). It should also be noted that at this time the theoretical complex methods of forming transient studies, particularly high-end bands are under development, require the development of complex and costly software computer systems.

References

  1. Клименко В.М., Балон Д.И., Юрченко Ю.И. и др. Определение утяжки концов полосы при прокатке в системе вертикальная – горизонтальная клеть // Изв. вузов. Черная металлургия.- 1980.- №4.- С. 66-68.
  2. М. Такаучи, О. Хирата и др./ Большое боковое обжатие при прокатке слябов/ 1987. – 57с.
  3. Никитина Л.А., Лебедева Л.А., Артамонова Е.А. Отчет о научно – исследовательской работе «Редуцирование слябов. Моталки».
  4. Чижиков Ю. М. Редуцирование и прокатка металла непрерывной разливки. – М.: Металлургия, 1974. – 382 с.
  5. статья «Редуцирование слябов по ширине»
  6. Долженков Ф.Е., Годсков В.П., Полторапавло Ю.В. Исследование эффективности использования клети с вертикальными валками // Усовершенствование технологии производства толстолистовой стали: Темат. отрасл. сб. – М.: Металлургия, 1981. – С. 49…52.
  7. Абэ Х., Саса К., Накагахара С. /Техника большого обжатия сляба по ширине при черновой прокатке на полосовом стане горячей прокатки и меры по уменьшению потер обрези./1983.
  8. Абэ Х. Методы уменьшения обрези при редуцировании слябов в черновой группе ШСГП.// Сосэй то како. 1984. Т. 25. № 2., с.87 – 92.
  9. Прокатка широкополосной стали. Сафьян М.М. – М.: Металлургия, 1969, с. 460
  10. Бровман М.Я. Усовершенствование технологии прокатки толстых листов / Бровман М.Я., Зеличенок Б.Ю., Герцев А.И. – М.: Металлургия, 1969. – 256 с.
  11. Прокатка на блюминге / И.Я. Тарновский, Е.В. Пальмов, В.А. Тягунов и др. – М. : Металлургиздат, 1963. – 389 с.
  12. Герцев, А.И. Условия деформации при прокатке раскатов в клети с вертикальными валками листовых станов / А.И.Герцев, И.М.Меерович // Труды Внииметмаш. – 1967. - № 18. - С. 13-17.
  13. Герцев А.И. Применение вертикальных клетей в листовых и полосовых станах для уменьшения разноширинности / А.И.Герцев, В.П.Калинин, И.А. Бернштейн, В.В.Гетманец // Сталь.- 1967. - № 9.- С. 828-831.
  14. Карнаушенко Н.А. Деформация металла в начальных ребровых пропусках на слябинге 1150 / Н.А. Карнаушенко, М.И. Капустина, А.М. Савченко // Сталь. – 1969. -№ 9. – С.804 – 809.
  15. Исследование некоторых особенностей деформации при редуцировании слябов : Теория прокатки / Н.А. Карнаушенко, М.И. Капустина, В.Д. Данилов и др. – М.: Металлургия. – 1975. –С. 400-401.
  16. Такада Кацуми / Влияние заднего натяжения при прокатке на форму конца сляба / Качуми Такада // Тэцу то хаганэ. – 1984.- 70.- №5.- С.427.