PSI - Issue 38

Alexander Erbe et al. / Procedia Structural Integrity 38 (2022) 192–201 Author name / Structural Integrity Procedia 00 (2021) 000 – 000

194

3

Figure 1: left side: used cruciform specimen; right side: servo-hydraulic planar-biaxial test-rig

The experimental campaign is carried out on the cast steel material G17CrMoV10-5 commonly used for stationary steam and gas turbines with the chemical composition given in Table 1. This steel was conventionally heat treated by a hardening procedure at 950 °C for five hours and a subsequent cooling in oil, an annealing at 730 °C for eight hours and subsequent cooling in air as well as a further homogenization at 700 °C for 5 hours. Figure 2 outlines the microstructure of the material, designated with the testmark sGZ. The grain-size varies between 7.6 and 9.6 according to ASTM E112. As gas turbine casings are significantly stressed by internal pressure and thermally induced stresses and strains during temperature cycles, multiaxial stress or strain states and their impact on lifetime are of particular interest for this application.

Table 1: Chemical composition of G17CrMoV10-5 (sGZ)

Element Fe

C

Cr

Mo

Mn

Si

V

Ni

Cu

Other

Mas.-%

95.68 0.193 1.308 1.048

0.696

0.505 0.242 0.174 0.051 Compl.

Figure 2: Microstructure of G17CrMoV10-5