"Impact of preheating on the mechanical performance of different MgO-C bricks- Low temperature range"

S.E. GASS; P.G. GALLIANO; A.G. TOMBA MARTINEZ

CERAMICS INTERNATIONAL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2021 vol. 47 p. 34869 - 34880

0272-8842

This work complements an initial study regarding the mechanical behavior of MgO-C bricks at 1000ºC. In this case, two bricks bonded with phenolic resin, one of them containing aluminum, were treated at 600ºC and mechanically tested at RT and 600ºC. The thermal treatments attempt to simulate the in-service steelmaking ladle preheating process. At low temperatures, the binder pyrolysis is one of the main transformations and the Al melting neither its chemical reactions occur on a large scale yet. To evaluate the effects as the pyrolysis progresses, the soaking time at 600ºC was varied from 1 to 3 hours. Although without significant chemical activity, the presence of Al affected the mechanical behavior of the tested bricks. The consolidation of the C-C network coming from the binder pyrolysis was identified as the main factor responsible for counterbalancing the material´´s degradation by microcracking. The heating combined with the low compressive pre-load applied on the tested specimens appears to close the microcracks and pores.