Lubricant composition for continuous casting processes

Continuous open casting of steel is a procedure widely operated in casting construction steel billets used to produce rods, wired rods and welded wire meshes. This procedure is frequently conducted without protection tubes of liquid steel stream between ladle, tundish and mold. Generally lubrication between steel strand and mold walls is obtained by using oil. Different kinds of oil have been historically used for this application, both natural, like rapeseed oil, and synthetic, such as fatty acids esters and polyalphaolefin. A new product has been developed to be used as lubricant in the mold instead of oil. This product is a dispersion of opportunely formulated continuous casting powder in a synthetic oil based on glyceric esters of fatty acids. Some additives have been added to the dispersion to control rheological characteristics. Target of this project was the development of a product which shows features of both oil and continuous casting powder. Extensive laboratory tests to measure physical characteristics of this product have been performed in order to sort out a well-defined and stable material. Industrial trials have been conducted using these new products and different benefits have been pointed out both in operations and in semis quality. A sharp decrease of sparkling phenomenon is observed which is connected with an improvement of operators safety, a reduction of mold cleaning operations and an increase in mold parts life. Regarding semis quality an improvement in shape of billets, a decrease of under-skin cracks and a decrease of sulphide precipitation have been observed. Other effects have been experienced such as a decrease in scale formation and a decrease in B/O index.