LIMITING THE SCATTER OF THE PROPERTIES OF HIGH-STRENGTH COLD-ROLLED SHEET

Objective. High-strength sheet steel grades are having to meet increas ingly stringent requirements with respect to the scatter of their mech anical properties for the automotive industry. Research into the micro structural evolution of these grades during their production was inten ded to provide information on which hot strip rolling conditions can l ead to a reduction of the scatter in the cold-rolled strip. Summary. T hyssen Krupp Stahl AG (TKS) has conducted laboratory and production-sh op trials to limit the scatter of the mechanical properties of microal loyed high-strength sheet grades. The most favourable way to produce s uch grades is in a continuous annealing line. If batch annealing is pe rformed, it is found that particularly an increase of the coiling temp erature at the end of hot strip rolling reduces the scatter of the mec hanical properties. There are plans to suitably modify the production practice for these steels at TKS so as to improve the future quality o f the sheet products. (E 29921).