EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

The increased demand for higher precision and lower tolerances of rolled steel products poses an enormous challenge for the development of roll materials. New high speed steel grades **HSS** offer a solution in many cases for hot strip mills, strip casters or plate mills because of their extreme wear and heat resistance as well as superior surface properties. For ***early roughing stands***, a new ***semi*-HSS** quality **SST-mod** is introduced providing extraordinary thermal stability in combination with reduced wear and optimum friction. Performance data will be presented. A new full **HSS** quality **SST** has proven its efficiency in late ***roughing, reversing roughing and early finishing stands***. With such new **SST** grades, surface quality and crown of the roll can be retained much longer, even in plate mills. The surface quality of the rolled product is considerably improved. The extreme wear resistance of new graphitised **HSS** grades also opens up opportunities for late finishing stands: ***Graphitised* HSS** materials called **SST-G** are increasingly used and provide significant improvement compared to conventional roll materials e.g. enhanced indefinite chill double poured ICDP. Dimensional accuracy and surface properties of the rolled products are much better and allow an increase in campaign length by a factor of two. Thus, the total cost of ownership TCO for the whole mill will be reduced.