Quality pyramid: Incre<strong>as</strong>ing <strong>quality</strong> demands <strong>for</strong>state-of-the-art <strong>advanced</strong> <strong>steel</strong> gradesAdvanced <strong>steel</strong>s: low production, lower economic pressure <strong>for</strong> <strong>steel</strong> producerbut high ancd mostly complex <strong>quality</strong> demandsAPI, GO-Si-<strong>steel</strong>s, SEDDQ, Roller bearing <strong>steel</strong>s, SHSS, ...Multiph<strong>as</strong>e (DP, CP, TRIP), valve <strong>steel</strong>s , spring <strong>steel</strong>s ...Deep drawing <strong>steel</strong>s (DDQ), ....High-strength low-alloy (HSLA), Press hardening, (PH), ...Rein<strong>for</strong>cing <strong>steel</strong>s, structural <strong>steel</strong>s, ....Commodity <strong>steel</strong>: high production, high economic pressure <strong>for</strong> <strong>steel</strong>producer and low <strong>quality</strong> demandsPRICM8 Bernhard 3 Quality pyramid: Incre<strong>as</strong>ing <strong>quality</strong> demands <strong>for</strong>state-of-the-art <strong>advanced</strong> <strong>steel</strong> gradesAdvanced <strong>steel</strong>sAPI, GO-Si-<strong>steel</strong>s, SEDDQ, Roller bearing <strong>steel</strong>s, SHSS, ...Quality demands:- Strength within small tolerances- Highest <strong>steel</strong> cleanness on macro- but also microscopic level- Homogeneity and internal soundness- High surface <strong>quality</strong> (Decarburization, inclusions, …)- …Commodity <strong>steel</strong>Rein<strong>for</strong>cing <strong>steel</strong>s, structural <strong>steel</strong>s, ....Quality demand:- Minimum strengthPRICM8 Bernhard 4
Outline of presentation Advanced <strong>steel</strong> grades: A challenge <strong>for</strong> processmetallurgists Macro- and mesosegregation in continuous c<strong>as</strong>ting On the nature of hot <strong>tear</strong> <strong>segregations</strong>: Formation andconsequence on product <strong>quality</strong> Physical simulation of HTS-<strong>for</strong>mation Numerical prediction of HTS-<strong>for</strong>mation in slab c<strong>as</strong>ting:Concept and example Summary Importance of c<strong>as</strong>ting process <strong>for</strong> the homogeneityof the final product, example DP600, 210 mm slabPresslinger, H., S. Illie, A. Schiefermueller, A. Pissenberger, E.Parteder, and C. Bernhard: ISIJ, Vol. 46 (2006), No. 12, 1845-1851PRICM8 Bernhard 6