Getting clean steel is becoming a major challenge nowadays, both for the production of competitive steel and for making easier the process exploitation. As a consequence, there is a need to study the behavior of solid particles (called inclusions) in liquid steel, responsible for the cleanliness defects observed in steel products. The addition to steel of a deoxidizing element such as aluminum provokes the formation of solid particles (Al2O3). These inclusions have a density smaller than steel so they can be eliminated by flotation and captured by the liquid slag layer on the steel surface. The paper proposes some mechanisms for the formation of inclusion cluster in liquid steel and examines the influence of the wetting condition on inclusion growth, using a cold experiment.