Magnesita

The most important recent technological evolution in the iron and steel industry occurred with the continuous casting process. From the initial replacement of conventional ingot teeming to the current “Near Net Shape” processes, the continuous casting end product quality requirements also continue to evolve, further increasing the process complexity.

Continuous casting is the last step in the molten steel process in the Steel Mill and because of this it is critical relative to quality. In this environment, Magnesita has constantly been updating its technology through internal developments and partnerships with universities and other high technology companies. These partnerships apply to both refractory product development and mechanical equipment items used in continuous casting, such as ladle shroud manipulators and tube changers. Thus Magnesita offers complete and integrated solutions to the customers. Among the partners is Krosaki Harima Co., which is a reference in the development and supply of refractory materials.

Steel Quality

The quality obtained in the steels produced through the continuous casting process begins with the opening of the ladle to transfer the steel into the tundish. In this stage, the ladle sealing sand performance is fundamental, providing the instantaneous steel pouring to the tundish, without the need to use oxygen.

High performance products

Magnesita has the Risablock® high performance product line of ladle sealing sands. One product in this line is the Risablock® DC, which is applied in two layers and is currently considered a world reference in free opening for stainless steels.

Ladle shrouds are used to protect the steel from re-oxidation during transfer from the ladle to the tundish. The ladle shrouds manufactured by Magnesita have excellent resistance to thermal shock, can be used without pre-heating, and can be reused multiple times. These features offers a significant cost reduction.

Tundish

In the tundish, the main objectives are to prevent the formation non-metallic inclusions and to maintain a homogeneous steel temperature. The tundish is gaining more and more importance in the steel process, with a decisive influence on the end product quality results.

In order to improve molten steel flow characteristics, which have a decisive influence on the mentioned objectives; Magnesita produces all of the refractory materials used in the tundish and is capable of determining the best configuration for each process by means of the use of computer simulation.

Tundish refractory

Among refractory items in the tundish, Magnesita’s Risaimpact® turbulence inhibitor with diffusing surfaces increases process stability, improves operational safety and promotes greater elimination of inclusions. When the inclusions reach the slag, it is important that this has good capacity to absorb them, obtained with use of Magnesita’s Coverflux® and Isodust® product lines.

Steel flow control

In the transfer of the molten steel to the mold, precise flow control is the most important factor. Magnesita has the capacity to offer all products and equipment for steel flow control, from refractory products such as nozzles and plates for sliding gate valves, up to the sliding gate valves and tube changer mechanisms themselves.

Shrouding of the steel stream and maintaining precise flow control in the mold are required for the production of quality steels. Magnesita supplies high performance submerged entry nozzles and shrouds for this requirement. In addition, it is capable of studying and proposing improvements through numeric simulation of the steel flow into the mold, which is an important tool for the production of high quality steels.