Publication detail

MINIMIZATION OF SURFACE DEFECTS BY INCREASING THE SURFACE TEMPERATURE DURING THE STRAIGHTENING OF A CONTINUOUSLY CAST SLAB

ŠTĚTINA, J. MAUDER, T. KLIMEŠ, L. KAVIČKA, F.

Czech title

Minimalizace povrchových vad zvýšením teploty povrchu v místě rovnání plynule litých bram

English title

MINIMIZATION OF SURFACE DEFECTS BY INCREASING THE SURFACE TEMPERATURE DURING THE STRAIGHTENING OF A CONTINUOUSLY CAST SLAB

Type

journal article - other

Language

en

Original abstract

Surface temperatures of cast slabs on small-radius segments as well as on the unbent areas belong to the parameters that affect the surface quality of continuously cast slabs. Older machines for continuous casting were designed with regard to the quantity (the amount of cast slabs) rather than the quality of the production. Therefore, an adaptation of the secondary cooling is required in order to obtain the desired surface temperatures. The modification consists of a dynamic control of the secondary cooling, surface-temperature monitoring by means of a numerical model of the temperature field as well as a prospective replacement of the cooling nozzles. In order to optimize and control the secondary cooling, characteristics of the nozzles, especially the influences of the water-flow rate, air pressure, casting speed, surface temperatures and heat-transfer coefficient under the nozzles have to be known. Moreover, the heat-transfer coefficient can also be influenced by the age of the nozzles. The paper deals with the relationships between these influences and their impacts on the temperature field of a cast slab. The results are presented for the 1530 mm x 250 mm slabs that are cast in Evraz Vítkovice Steel where the main author's dynamic, 3D solidification model is used, in its off-line version, to control the production interface. The results can be used for the preparation of a real casting process.

Czech abstract

Povrchové teploty litých bram na malém radiusu, patří k parametrům, které ovlivňují kvalitu povrchu plynule litých bram. Starší stroje pro kontinuální lití byly navrženy s ohledem na množství odlitých bram než na kvalitu výroby. Z tohoto důvodu, je adaptace sekundárního chlazení, aby se dosáhlo požadované teploty povrchu.Modifikace spočívá v dynamickém řízení sekundárního chlazení, povrchově monitorování teploty pomocí numerického modelu teplotního pole, stejně jako potenciální nahrazení chladicích trysek. Aby bylo možné optimalizovat a kontrolovat sekundární chlazení, charakteristiky trysek, zejména vlivům na vodní průtok, tlak vzduchu, rychlost kouzlení, povrchových teplot a přestupu tepla součinitel za trysky musí být známy. Kromě toho, může být součinitel přestupu tepla být také ovlivněna v závislosti na věku trysek. Příspěvek se zabývá vztahy mezi těmito vlivy a jejich dopady na teplotního pole odlitku desky. Výsledky jsou prezentovány na 1530 mm x 250 mm desky, které jsou zalité v Evraz Vítkovice Steel, kde se používá hlavního autora je dynamický, 3D tuhnutí model v off-line verzi, ovládat výrobní rozhraní. Výsledky mohou být použity pro přípravu skutečného lití.

English abstract

Surface temperatures of cast slabs on small-radius segments as well as on the unbent areas belong to the parameters that affect the surface quality of continuously cast slabs. Older machines for continuous casting were designed with regard to the quantity (the amount of cast slabs) rather than the quality of the production. Therefore, an adaptation of the secondary cooling is required in order to obtain the desired surface temperatures. The modification consists of a dynamic control of the secondary cooling, surface-temperature monitoring by means of a numerical model of the temperature field as well as a prospective replacement of the cooling nozzles. In order to optimize and control the secondary cooling, characteristics of the nozzles, especially the influences of the water-flow rate, air pressure, casting speed, surface temperatures and heat-transfer coefficient under the nozzles have to be known. Moreover, the heat-transfer coefficient can also be influenced by the age of the nozzles. The paper deals with the relationships between these influences and their impacts on the temperature field of a cast slab. The results are presented for the 1530 mm x 250 mm slabs that are cast in Evraz Vítkovice Steel where the main author's dynamic, 3D solidification model is used, in its off-line version, to control the production interface. The results can be used for the preparation of a real casting process.

Keywords in Czech

optimalizae teplotním polem, povrchová teplota bramy, charakteristika trysek, plynulé odlévání oceli

Keywords in English

optimization of the temperature field, surface temperature of a slab, characteristics of nozzles, continuous casting

RIV year

2013

Released

28.06.2013

Publisher

IMT Ljubljana

Location

Ljubljana

ISSN

1580-2949

Volume

47

Number

3

Pages from–to

311–316

Pages count

6

BIBTEX


@article{BUT100344,
  author="Josef {Štětina} and Tomáš {Mauder} and Lubomír {Klimeš} and František {Kavička},
  title="MINIMIZATION OF SURFACE DEFECTS BY INCREASING THE SURFACE TEMPERATURE DURING THE STRAIGHTENING OF A CONTINUOUSLY CAST SLAB",
  year="2013",
  volume="47",
  number="3",
  month="June",
  pages="311--316",
  publisher="IMT Ljubljana",
  address="Ljubljana",
  issn="1580-2949"
}