Production of high quality formable grades in an ultra short annealing processing line

A flexible and compact continuous annealing line, having the possibility to adapt very quickly the annealing parameters to the grades and/or formats to be produced, should reduce yield losses due to transient parts of the coils compared to conventional continuous annealing. Such a compact annealing line makes use of the latest heating and cooling technologies. An ultrashort annealing line where the strip is coiled at a rather low temperature can result in the correct mechanical properties on ELC-steels in order to produce an ageing-free DQ-quality. A texture memory is observed for Mn-P added IF-steel after a double α-γ-α transformation. The massive ferrite induces an important increase of the mechanical properties but the elongation is greatly reduced. The compact and flexible annealing cycle, including a plateau at around 650°C after a conventional soaking stage in the intercritical temperature range, is very suitable for the production of formable, cold rolled dualphase steels. This cycle is very robust since the mechanical properties do not change if the soaking temperature or the primary cooling rate changes. Very promising mechanical properties were obtained from very simple steel without any Cr or Mo additions. An ultrashort annealing cycle can also be used for the production of packaging steels. For the ultralow carbon steels, an improvement of the Lankford coefficient was observed for the heating rate of 100°C/s and higher tensile properties were obtained compared to standard continuous annealing (CA). For the low and medium carbon steels, USA either induces similar or lower mechanical properties after USA compared to after CA.