The C.I.T.-CIREP Test was designed to simulate the service conditions of refractories when simultaneously exposed to corrosion, mechanical impact and thermal shock. The test procedure is given below.

A special refractory crucible is used (Fig. 1), about its periphery and into which multiple specimens are placed. This allows, within the same environment, to submit individual specimens to one of the following treatment :

      • Full immersion into pure molten metal or alloy (no thermal shock & no impact)
      • Full immersion & thermal shock
      • Full immersion & mechanical impact
      • Thermal shock (no immersion)
      • Reference specimen

Thermal shocks are produced by placing the hot specimens on a water cooled copper plate. Mechanical impacts are generated by dropping a 230g stainless steel rod on the middle of specimens while they are simply supported (Fig. 2).

This test lasts five days. On day one, the crucible containing the molten metal and the six 2,5 x 2,5 x 15 cm specimens, two being notched, are introduced into a furnace which is then heated at 815°C after which the three specimens met to be exposed to liquid aluminium are introduced in the melt. On day two, a series of thermal shocks is performed and the molten metal alloy composition is adjusted, if required. One day three, a second series of thermal shocks is performed and another molten metal composition adjustment is made, if required. On the fourth day, the last series of thermal shocks is made and the two mechanical impact tests are performed. The dynamic modulus of elasticity (E) and the weight are measured each time a specimen undergoes a thermal shock. On day five, the specimen exposed to corrosion only is removed from the melt and the melt and the furnace is cooled down slowly. Once cold, the corroded specimen and the reference specimen are taken out and their modulus of elasticity is measured.

Corrosion ratings are given according to criteria based on the extent of adherence, penetration, friability and cracking observed. Thermal shock and mechanical impact ratings, with and without corrosion interaction, are given based on the lost of elastic properties.

* For more information about this section, please consult the following reference:

ALLAIRE, C., INNUS, A. and PELLETIER, R, "Interaction of refractory Thermo-Physical Properties with Molten Al-5%Mg", Advances in Refractories for the Metallurgical Industries IV", CIM Proceedings, ed. by M. Rigaud and C. Allaire, pp 251-260, August 2004