In-line rolling and cooling of direct cast steel strip

Twin roll strip casting is being under development as a process for alterna tive hot strip production. Now, the marketing and the commercial production phases have been started. Rapid solidification, low hot strip thickness an d the chances of in-line-treatment between easter and coiler all contribute to the potential of this casting process, For several steel grades good mechanical strip properties will already be o btained in the as-cast state or after an annealing process if the cooling c ycle of the strip is adjusted to the steel grade, as far as the phase trans formation behaviour is concerned. Another metallurgical potential is brough t about by incorporating an in-line hot rolling step. Investigations in thi s field carried out by Thyssen Krupp Stahl AG and the institute for Metal F orming (IBF) of RWTH Aachen led to the following results: unwanted hard mic rostructure phases are avoided, grain diameter is decreased, micropores are closed and low final strip thickness is achieved. The transferability of the research results to industrial strip casting fac ilities is given, and the routes of strip casting, laboratory experiments a nd numerical simulation methods are ready for further development of both t he material and process.