Prakt. Met. Sonderband 52 (2018) 215 
ations 
ls 22240 
lng doy 
, fer wi 
days Cary 
Miiched during 
» Molybdenum a 
thoy Fig. 2: (a) SEM image (back scattered electrons) of the segregation area with martensite, 
rh od (b) Inverse Pole Figure (IPF) image of crystallographic orientations in the marked area 
Saha from (a), (c) Image Quality (IQ) image of the marked area 
An EDX mapping of the element distribution in the microstructure was performed in SEM. 
Due to space limitation only the distributions of iron (Fe), Mo and Cr are presented in this 
paper (Fig. 3). As expected, the accumulation of Mo and Cr instead of Fe led to the locally 
limited martensitic transformation during cooling down process. 
bainitic 
eraha Il in the ; 
Fig. 3: Element mapping, distribution of Fe, Mo and Cr in the segregation area with 
martensite 
2.2.2 MICROHARDNESS MEASUREMENTS USED FOR DETERMINATION OF LOCAL 
PROPERTIES 
n fer 
x hi The properties of the selected phases (stress-strain curves) used in FE simulations were 
sige : extracted from the instrumented Vickers-microhardness measurements based on 
ss Us algorithm described by Dao in [3]. For the investigations, a universal hardness testing 
i” neti machine ZHU/zwickiLine+ from Zwick/Roell was used. The indenter was placed precisely 
ak ona in the different individual phase areas (Fig. 4a). 
and Cr in the 
#0 23 FE SIMULATIONS 
nthe ROL 
oo 2.3.1 CREATION OF MICROSTRUCTURE BASED FE MODELS 
Based on the Image Quality presentation (Fig. 2c) in combination with the results from 
EDX measurements and optical microscopy a microstructure based 2D simulation model 
was created (Fig. 5a). The FE model consists of 56,840 CPE4 elements and 4 element 
sets corresponding to microstructural constituents or phases: ferrite. bainite, martensite