Continuous casting lines are exposed to extreme temperature and corrosion. UTP developed the alloy WEARcore 768-S to double the lifetime of CC top rollers.
At the topmost part of the continuous casting line, thermal shock, corrosion, and hot oxidation are most severe, while mechanical wear is still low. For this reason, it is accepted to apply overlay materials with a lower hardness, but with increased corrosion resistance. Super-martensitic stainless steels have a much better corrosion resistance than classical martensitic types combined with acceptable wear behavior.
One of the severest corrosion mechanisms taking place here is due to the accumulation of fluorine and alkaline casting powders in the cooling water, the so-called mould-flux-induced-corrosion. In this area, soft martensitic stainless-steel overlays are a commonly applied solution and therefore formed the benchmark in development. The cored wire was extensively tested at the Dillinger Hütte steel works, in Germany.
Following targets were specified for the properties of the new solution:
Results of laboratory and field tests summarized are:
