Producing cold rolled strip with good deep drawing properties - by subjecting strip to holding phase during heating up at 590-600 deg.C.

摘要

Method of producing cold rolled steel strip with a composition according to the Euronorm EN 10130 from Al-killed steel slab having a N2 content above 60 ppm which is subjected to a single gamma/alpha transformation in which the cold rolled strip is discontinuously heat treated, e.g. in a dome-shaped annealing furnace. During heating up it is held at 590-600 deg.C for a specific time (at least one hour) depending on the N2 content and the degree of cold rolling (at least 60%). The holding time enables the precipitated aluminium nitride particles to grow but with a low degree of dispersion. ADVANTAGE - Cold strip has good deep-drawing properties with improved elongation (at least 40%) and low yield strength (up to 190 MPa).