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UTP super-martensitic cored wire used for concast rollers in steel meels - WEARcore 768-S / RECORD SK

2024-04-04 | 

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.

New solution supermartensitic weld overlays

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.

UTP has developed a special overlay material for the first series of rollers in the vertical section, directly after the mould of the continuous casting process:

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:

  •  Improved wear resistance in primary roller section.
  •  Martensite starting temperature far above room temperature to facilitate full transformation.
  •  No influence of dilution with base material in the third layer
  •  Delta Ferrite content below 10% (point counting method)
  •  Suitability for small roll diameters, typically 150-300 mm
  •  Good slag release at temperatures of 300-350°C

 Results of laboratory and field tests summarized are:

  • The supermartensitic overlay with WEARcore 768-S and RECORD SK doubled the lifetime of the overlaid roll ers in the first segment of the continuous casting line at Dillinger Hütte steel works.
  1. The molten steel can be tapped from the bottom of the ladle into an intermediate container known as the tundish. The temperature of the melt is now below 1,600°C.

Product features

WEARcore 768-S - EN 14700 T Fe7


  • SAW cored wire specially designed for hardfacing of top zone rollers
  • Improved wear & corrosion resistance
  • Self-releasing slag
  • Microstructure: martensite & ferrite & residual austenite
  • Hardness as-welded: 36 HRC

Customer benefits:

  • Doubled lifetime of the top zone rollers
  • Good machinability with metallic carbide tipped tools
  • Cost efficient method of overlaying