METHOD FOR TREATING A STEEL STRIP

摘要

The present invention relates to a method for treating a steel strip, particularly a steel strip made of highly resistant heat-treated steel, by cold rolling. The inventive method comprises at least a first step of heat treatment consisting of recrystallization annealing and at least another subsequent step of heat treatment consisting of hardening. Said method is characterized in that the time-temperature curve during the first step of heat treatment is chosen in such a way that only a partial recrystallization takes place and that the elongated structure produced by the previous strain-hardening is partially conserved. The inventive method enables reducing significantly the annealing time and annealing temperature during recrystallization annealing while at the same time reducing the annealing time during shape hardening. The processing chain can be reduced by more rapid annealing cycles, the reduction of the annealing temperature leading to significant energy savings. Said method allows producing e.g. semifinished sheet metal products for vehicle body components having an optimized strength/elongation ratio.