Třinecke Železarny a.s., Třinec, Czech Republic:

Milata R., Eng., Steel Production Technologist

Bajtek P., Eng., Production Manager, Continuous Casting

Lacina L., Eng., Head of Continuous Casting

Bocek D., Eng., Steel Production Technologist

Cupek J., Eng., Senior Steel Production Technologist

SMS Concast AG, Zürich, Switzerland:

Kawa F.,  Dr. Min., Head of Project, Research and Development,  franz.kawa@sms-concast.ch

The Invex mould is a new tubular mould concept for the continuous casting of steel. The paper summarizes the three-year operational experience at Třineckè Železàrny using this system for a daily industrial production of large blooms on a five-strand bloom caster. main data of continuous casting machine No. 1 and product mix of steel grades for 300·350 mm section size are presented. Top view of plate mould is analyzed with visible corner gaps after operation. Examples of surface and microstructure defects on continuously cast blooms are examined and it was revealed that these defects were caused by mould corner gaps. Construction of mould cartridge and continuous casting machine head equipped with plate mould are displayed. Temperature distribution in strand shell during solidification within continuous cast mould and equivalent (von Mises) stress in strand shell during solidification within continuous casting mould are detected for moulds with 45^o chamfered corner and with special rounded corner. Surface quality of blooms in comparison of plate mould vs. Invex mould is searched as well as weight ratio of defect-free blooms in comparison of plate mould vs. Invex mould. Recalibration process of mould copper tunes is displayed. 

1. Cienciala, J.: 160 let Třineckych Železaren: Hutnicke listy 62 (1999) Nr. 6, S. 3/4.

2. Lu, M. J; Chang, C. Y.; Hung, C. H.; Chen, C. H.:  Minimization of offcorner longitudinal cracks in con tinuous cast blooms, Proc. SEAISI Conference, Bangkok, Thailand, 29. Juli — 1. Aug. 2003, S. 1/11.

3. Luttenberg, M.; Andre, B.; Kirsch, D.; Kawa, F.; Rohrig, A.: Concast integrated mould for CC of blooms — first experiences at Arcelor-Mittal Ruhrort, Proc. 6. Europ. Continuous Casting Conf. (ECCC 2008), 4.–6. Juni 2008, Riccione, Italien.

4. Tercelli, C.; Kawa, F.:  MPT Intern. 31 (2008) Nr. 6, S. 40/42.

5. Grundy, A. N.; Kawa, F.; Kundig, B.; Hogenschurz, M.:  Von Convex bis Invex, Proc. 7. Europ. Continuous Casting Conf. (ECCC 2011), METEC InSteelCon, 27. Juni — 1. Juli 2011, Düsseldorf.