Prakt. Met. Sonderband 38 (2006) 343
eration - 3.2 Mechanical Properties
wn to be
he steel. The mechanical properties measured are presented in Table 3. The applied heat treatment
carbides results in an average hardness of 58 HRC. High hardness is achieved after quenching, but
steel and HRC decreases considerably due to the high tempering temperature employed.
structure. Furthermore the microhardness of the matrix and of larger carbides was determined. It
th some was twice as much for the alloy carbide than for the matrix, which corresponds with results
ere also in the work of Pernegger [12], who found a microhardness of 1500 when the carbide
using 11 contains 70 mass% iron, and for plain chromium carbides Cr;Cs; 2200. Pernegger
sented in observed the microhardness for this carbide type decreasing with increasing amount of
scarcely iron. Dynamic Young's Modulus of the chromium alloy carbide, which has been taken from
diameter. Ref. [13], is about 100 GPa higher than for the studied steel. T.R.S. determination
ig image revealed relatively high strength for this hard material. Fracture appears to be ductile with
cation. It some transgranular fracture i.e. of the carbide particles. Cleavage of the primary carbides
‘al [4]. It was found at the entire fracture surface. ) }
Rockwell Hardness Micro-Hardness T.R.S. Dynamic Young’s
Steel HRC 150kg (HV 0.25N) (MPa) Modulus (GPa)
ee = — ER —— —————— Ce ————————— ie
as- ! alloy tempered | tempered Cr;Cs
tempered matrix
quenched carbides steel steel Ref. [13]
1.2379 | 64 58 754 1500 3600 210 320
Table 3: Measured mechanical properties of the studied steel.
1100
1g fine-
s alloy 1000
A
a 900
A Oo A AO
© 800 A AA © a Oo
; 0 AQ
; 700 9 0
J AOO © ®
5 600 O@E A O ©
500
herical,
rs can
1,E+05 1,E+06 1,E+07 1,E+08 1,E+09 1,E+10 1,E+11
0 number of cycles
Figure 7: S-N curve of X155CrVMo12.1 cold work steel at stress ratio R = -1 and 20 kHz
test frequency. Fracture modes: internal fish-eye fracture (A), near-surface fracture (o),
mc surface defects (e). Runouts at 10E10 (4).
