Recarburisers

Recarburisers are used in high-grade steel, grey and ductile iron castings. Elkem’s Elgraph® recarburisers has proven to give the best performance on dissolution rate, carbon recovery and with the lowest nitrogen/hydrogen content. The unique production technology, located in Norway, is the foundation for the high quality carbon additives.

Benefits

Elkem is the preferred supplier for leading companies in the steel and casting industry. 
Advantages of the Elgraph® recarburisers are:

  • High carbon recoveries
  • Easily rapid solubility even at low agitation
  • Consistent quality due to continuous production process
  • Carbon trimming just prior to casting
  • Very low nitrogen/hydrogen levels reduce pinhole risk

Research and development has resulted in a new generation electric calciners, operating continuously at very high temperatures (up to 3000 °C), creating a carbon raiser with high purity, excellent solubility and high carbon recovery that contribute to a more cost efficient production of castings. 

Customer value

Economy and cost effectiveness are key words in the foundry and steel industries, and the selection of recarburisers strongly influences this. Key requirements are

  • high carbon yields  value for money
  • less slag  improved operations, reduced power cost
  • dissolution rate  energy costs and tap-to-tap times
  • reproducibility planning, automation and fewer rejects
  • lining life  economy and down-time

About Elgraph

The technology developed for Elgraph is capitalising from the production of 100 years Elkem electrode paste production for selecting, control and testing raw material to control and optimize the production based on customer needs. 

The high calcining temperature allows Elkem to produce a purer and more graphitised product. It is generally found that the more graphitised the recarburiser, the better the carbon recovery and solubility. 

As a measurement for the degree of graphitisation the electrical resistance can be used. Practical foundry experience has shown that solubility can be related to the degree of graphitisation, which is related to the resistivity of the recarburisers. Typically a good solubility recarburiser should have a resistivity of less than 270 µOhm. 

The new calcining technology allows the production of recarburisers with very low levels of sulphur, nitrogen, hydrogen, volatile matters and ash. Its high dissolution rate makes it very suitable in the carbon adjustment phase of metal preparation. 

Elgraph® recarburisers products are widely used in the manufacture of cast irons and in steel production in almost all continents.

Elgraph® Superior recarburiser

Elgraph® Superior recarburiser is specially formulated as a low sulphur, high purity carbon raiser for the most demanding ductile iron and steel making processes. It may also be used for final trimming of grey iron. Its high dissolution rate makes it very suitable in the carbon adjustment phase of metal preparation.

  • Elgraph® Superior recarburiser has a typical electrical resistivity of 50 - 60 µOhmm.
  • Elgraph® Superior recarburiser is available in size grading 0,5 - 5 mm and 0,5 - 5 mm.

Elgraph® Premium recarburiser

Elgraph® Premium S Recarburiser is specially formulated as a carbon raiser for steel and grey iron castings, with particular emphasis on high purity, low content of nitrogen and hydrogen, rapid solubility and good reproducibility.

  • Elgraph® Premium recarburiser has a typical electrical resistivity of 100 -300 µOhm.
  • Elgraph® Premium recarburiser is available in size grading 0-0.5 mm and 0,5 - 5 mm.

Elgraph® Premium Steel (Premium +) recarburiser

Elgraph® Premium Steel recarburiser is similar to Premium, but especially formulated as a recarburiser for grey iron and some steel types to give an even lower nitrogen content, as well as lower sulphur level for steel manufacture. Its high dissolution rate makes it very suitable in the carbon adjustment phase of metal preparation in foundries and steelplants.

  • Elgraph® Premium Steel (Premium+) recarburiser is available in size grading 0,5 - 5 mm and 5 - 8 mm.

Typical values

Typical values
 % Fix C % S % N % H % Volatile % Ash 
Elgraph® Superior Grade   99.9 0.01 0.01 0.001 0.01 0.04
Elgraph® Premium  99.1 0.35  < 0.1 0.01  0.1  0.4 
Elgraph® Premium Steel   99.3 0.25  < 0.1  0.007  0.07  0.3