Prakt. Met. Sonderband 46 (2014) 93 
at this “abnormal” um. The fractions of these grains are about ~ 30% of the 
oriented steels [5]. total area of the sample. Moreover, all the huge grains 
ds by dislocations are located near the surface of the sheet plane with 
deformation impress. 
As one can see from the Fig. 5a and Fig. 5c, the 
regions with huge grains in both pictures are completely 
different near the deformation impress. In the first case, 
deformation of about e~ 2.2% was applied. The grain 
size of the huge grain is ~ 350um and they growth near 
- the area of applied deformation, see Fig. 5a. The sizes 
on gradient after of these grains are match bigger than the size of 
nges from € -0% , surrounding grains. The mentioned grain growth features 
-6% deformation : leads one to suggestion of abnormal grain growth 
ie rm bert nbd character of grains located near the surface of the steel 
s.4a and 4b. The sheet. The Fig. 5c represents microstructure of the 
ns that the sample samples area with maximum impress deformation of e~ 
tion of deformation 6.8%. Here, the grains located in the impress 
ation. The sadden deformation region have grown through the whole 
this area changes thickness of the investigated steel sheet. The size of 
inges are reflected these grains is about 400 — 500 um. 
e microstructure of b) The experimental materials with impress deformation of 
he region with 4% Fig. 6 Local misorientation £- 3,8 % is shown in Fig. 5b. The huge grains have 
have much larger map obtained from EBSD grown also under of applied impress deformation area. 
mean grain size in analysis of the investigated However, the grain size depends on the value of applied 
| grain size of the sample F1A with impress impress deformation. After analyses off all pictures in the 
g. 4a, respectively. deformation (a), local Fig. 5, one can to conclude, that grain size directly 
%. As one can see misorientation distribution of depends on the value of impress deformation. On the 
verage size of the the microstructure (b). other hand all the observed huge grains grow to 
n Fig.4b does not opposite direction of strain increasing. It means that 
| in previous case, grain boundary motion has directional character. 
here is a particular These facts lead ones to conclusion that applications of 
eel, from grain size particular deformation to the samples in combination 
with heat treatment leads to activation of controlled 
jated material with grains growth in the investigated materials, see Fig. 5. 
Fig. 5. As one can Local misorientation map obtained from EBSD analysis 
erated in this way performed on impress deformation area of the 
> the impress was investigated sample before temperature annealing is 
oundary motion on CT presented in Fig. 6a. Local misorientation map is 
Fig. 7 PF map of the gisplaying small orientation changes on the map, 
after application of Investigated sample F1A highlighting regions of higher deformation. Hence, the 
» min., see Fig. 5. It after application of impress Fig. 6a represents an analysis of stress (or dislocation 
je a precise line of deformation of £~3.8% and density) distribution in the region of applied impress 
ins (grain size ~ 25 heat treatment at 900°C for 2 deformation. As one can see, there are different areas 
process of second min. with different values of local misorientations. According 
is about 200 — 500 to the key, see the Fig. 6b, higher stress has been 
accumulated in the surface region where the impress deformation was applied. The 
intensity of the generated stress decreases through the whole thickness of the sample. 
These confirm a fact that there is a gradient of accumulated stress through cross section 
of the steel sheet generated by impress deformation. 
The IPF map of longitudinal cross section of the investigated steel with impress 
3.8%, ¢) £~6,8% deformation after heat treatment at 900°C for 2 min is presented in Fig. 7. This IPF map 
‘mosphere.