Steels_ Metallurgy and Applications, Third Edition

14 Steels: Metallurgy and Applications

Figure 1.9 Stereographic projection illustrating the relationship between the crystal
coordinate system [1001,[010],[0011 and the specimen coordinate system, the rolling,
transverse and normal directions, by rotations through the Euler angles, qbl, cp, qb2 using a
(111)[ 1211 orientation as an example (Hu 23 )

r 54"7~ ~ x (RD) J _

#,2 =45 * .(111) [121]

Figure 1.10 Diagram of orientation space showing the important section at ~2 = 45*
containing the ct fibre orientations ((1 I O)//RD) and the y fibre orientations ((111)HND
(Emren et al. 24)

set of orientations represented by a straight line parallel to one of the axes in
orientation space is known as a fibre texture. Figure 1.10 gives the position of
the y fibre texture, which includes all orientations with a [ 1 1 1] direction normal
to the strip surface and the t~ fibre texture, which includes all orientations with a
[110] direction in the rolling direction. These two fibre textures are particularly
important since, as mentioned previously, they have a dominant influence on the
r values and hence deep drawability of a ferritic steel.
A limitation of all the above three methods of representing texture is
that the methods characterize the average texture in the volume of sample
examined, but give no indication of the spatial distribution of grains with a