Abstract

Tundish is the last equipment in contact with liquid steel which is relined with refractory with the possibility of affecting the steel quality. In this equipment the working lining plays the role of thermal container. Despite the concerns about H2 pick up that can be caused by the presence of water and also an excessive consumption of gas for drying and heating, spray mixes have been a dominant technology for tundish application. Almost 90% of the plants in South America use this kind of refractory lining. In the last 20 years new technologies came up to the market with the proposition of reducing or even eliminating the need for water and gas, making the application easier and increasing tundish availability. Although these new technologies present these advantages over the spray mixes and are useful for some operational conditions, spray mixes still have a strong presence in the market mainly due to their low cost and high thermal insulation. Nowadays, some improvements have been developed regarding the dry and spray mixes in order to have a more complete and suitable technology to fit the most specific demands from the market. However, some operational conditions that ensure the desirable working lining performance are as important as having appropriate technologies. The slag attack, stream deviation, and an application of a thin layer during the tundish relining are examples of operational variables that affect the performance of the tundish despite the technology used, and can be avoided. In this way, product technology, application procedure and process conditions are pillars of success and must move together.

Key words: continuous casting, tundish working lining, spray mixes, dry mixes