Materials Science Forum, Vol.426-4, 1349-1353, 2003
Deep-drawable steel strip produced by ferritic rolling
To produce a thin gauge hot strip with desirable deep-drawing properties a ferritic rolling strategy, in which the finish rolling temperatures are shifted into the ferritic region, can be utilised. Two different ferritically rolled products, a "soft" hot strip and a "hard" hot strip of a commercial IF steel, were produced on a laboratory rolling mill. The "soft" hot strip was rolled in the upper ferrite temperature region and thus directly recrystallised in the coil. The "hard" hot strip, rolled in the lower ferrite temperature region, exhibited a strained microstructure and therefore required a supplemental annealing. The guidelines for the optimum ranges of process parameters were determined in previous investigations by using the plane-strain compression test on the hot deformation simulator WUMSI. Roll lubrication was utilised during all ferritic rolling tests, to diminish the detrimental influence of friction on the texture near the surface. The microstructure and texture investigations together with the measurement of mechanical properties, including the Lankford values, could be used to establish the process parameters necessary to significantly improve the deep-drawing properties. In the ferritically rolled strip, the properties could be adjusted as to be comparable to those of steel grade DC 04 and even DC 05.