The tundish is the final stage in the steelmaking process when the steel is still in molten form. After the tundish, the steel is cast into a solid form. Therefore, the tundish is a very critical process in terms of the purity of the steel. 

Ovako Imatra manufactures specialty steel for clients such as the automotive industry, and the company has precise purity criteria for the quality of its steel. At Imatra, the use of dry mix in tundishes was introduced in the 1990s.

Improved quality as requirements increase

Bet-Ker Oy has been involved in the development of Ovako’s tundish lining since dry mix was first introduced. The lining material and the tundish process have been modified as the purity requirements for steel have become stricter.

The current lining material has Bet-Ker’s inorganic binder, which achieves extremely low hydrogen concentrations. Other advantages of the binder include the fact that the steel shells of the tundishes have not rusted as they did with the resin used in the past.

Optimal results through experimentation

While magnesia is still used as the main aggregate material of Ovako’s tundish liner, other raw material sources have also been tested. The advantage of testing a number of raw materials is that they can be reliably exchanged if the availability of some of the materials is impaired. 

With the development work, the raw material is now very light, resulting in a low level of thermal conductivity, which improves the quality of the steel. At the same time, the particle size distribution of the liner has been modified to ensure that the liner is as tight as possible. 

As a result, the steel cannot penetrate the lining even with long casting sequences. Better compacting of the mass also improves the surface quality of the lining.

Continuous development, guaranteed

The cooperation between Ovako and Bet-Ker in the tundish development process continues. The next step is to optimise the lining thickness in the different parts of the tundish.

We achieve the best results by closely cooperating with the client!