In the first part of this work, AISI H13 substrate samples were
quenched and tempered to a hardness of 47 HRC. After the heat
treatment the H13 specimens went thought low pressure gas
nitriding process. The nitriding temperature was fixed at 520 °C
while the nitriding time varied from 5 to 9 h. In the nitriding process
the goal was to obtain two different nitrided cases with different
surface hardness and nitrided case depth as well. These two nitrided
cases will be referred as case A and case B. The phases formed during
the nitriding process were revealed by performing XRD inspection in a
Shimadzu XRD-7000 diffractometer. The nitrided cases hardness profiles were obtained by performing Knoop indentation using a load
of 0.98 N in a Shimadzu HMV Micro Hardness Tester. The nitrided
cases depth was determined by adding 1 GPa to the hardness base line
in Fig. 2.