INFLUENCE OF GRAIN-REFINEMENT OF HOT-BAND ON ROLLING AND RECRYSTALLIZATION TEXTURES OF PLAIN EXTRA LOW-CARBON STEEL SHEETS

The effect of the hot band grain sizes of 28 mu m and 54 mu m on the r value and the texture formation of cold rolled plain extra low carbon steel sheets has been investigated in a range of cold rolling reducti ons from 70 to 90%. The results are concluded as follows. 1. In the fo rmation of the cold rolling texture, the refinement of the hot band mi crostructure increases the intensities of the orientations in the vici nity of {111}[112] and {100}[110]similar to{112}[110], which indicates that the grain refinement of the hot bands plays a similar role like an increase in the cold rolling reduction. This phenomenon can be expl ained by the development of a sharp hot band texture and the constrain t of deformation due to the increased grain boundaries. 2. The main or ientation of the recrystallization texture changes from {111}[110] to {111}[112] due to the increase in cold reduction. The former might be preferred by the nucleation and the latter by the growth process. The grain refinement of hot band shifts this transition to a lower reducti on. 3. Proper combinations of high reduction cold rolling and the grai n refinement of the hot bands makes it possible to produce a excellent good deep drawable plain extra low carbon steel sheet with high r and low Delta r.