• Watzinger, Irene
• Bernhard, Christian
• Watzinger, Josef
• Presoly, Peter
• Linzer, Bernd

Abstract

The Arvedi ESP process and a variety of produced materials have been continuously developed since the opening of the Arvedi ESP plant in Cremona in 2009 to meet market demands for more sophisticated steel grades. The development of grades for more advanced applications such as advanced high strength steels and multiphase grades is of interest. Dual phase grades such as DP600 are already produced through an ESP line on an industrial scale; additional multi-phase grades such as TRIP are under development. High-strength steels for the automotive industry have especially high demands on material properties. In addition to the mechanical material properties, an excellent surface quality is required. The fundamental basis for such material properties on rolled coils needs to be provided from continuous casting. This paper deals with the classification of different – either Si- or Al-based – alloying concepts for TRIP steels with respect to their prospective behaviour in a thin slab caster. The investigated alloys are characterized by means of experiments, measurements, thermodynamics and phase transformation kinetics. The phase transformation sequence during solidification, the tendency towards internal and surface defect formation, the expected inclusion population and the presumed interaction with mould fluxes are considered. In addition to the selection of suitable alloying concepts, the process stability regarding high mass flow rate for good temperature guidance, consequent product homogeneity, minimum inclusion content and stable mould level for the highest surface quality are of outstanding importance. The high technical and economic potential of the Arvedi-ESP process to produce AHSS steel grades indicates significantly expanding production in the future.

Topics

• impedance spectroscopy
• surface
• inclusion
• phase
• experiment
• strength
• steel
• solidification
• continuous casting