ABSTRACT

In this paper, the development of a new grade of structural austenitic stainless steel by conventional continuous casting and its metallurgical background are reported. This steel belongs to the family of high nitrogen steels, and the main criticalities encountered during its development and industrialization have been the nitrogen solubilisation during the solidification process, the volume fraction control of delta-ferrite phase during the slab reheating before hot rolling, and the limitation of grain growth during the annealing processes. All the mentioned aspects have been treated taking into account predictions of thermodynamic and physical models, thus permitting the production of flat products with the desired mechanical properties, free of defects and with a good surface quality. The mechanical and corrosion resistances of the developed steel has been assessed and at the moment it is proposed by TK-AST in several fields, comprising automotive, ballistic and fire resisting applications.