PSI - Issue 68

1126 6

Birhan Sefer et al. / Procedia Structural Integrity 68 (2025) 1121–1128 Sefer et al. / Structural Integrity Procedia 00 (2025) 000–000

Figure 5. SEM-images showing the typical appearance of the fracture surface of AM Hastelloy SSRT specimens tested at room temperature with a) argon and b) hydrogen gas.

Figure 6. SEM-images showing the typical appearance of the fracture surface at AM Hastelloy SSRT specimens tested at 800°C with a) hydrogen gas and b) argon.

The measured hydrogen content in the specimens after SSRT in H 2 at both temperatures compared to the hydrogen content in the materials in as-received state is shown in Figure 7. There was notable difference in the hydrogen contents measured in as-received state between conventional and AM manufactured materials. The reason for this can be ascribed to the different manufacturing process as well as to the microstructure according to Gao et al. (1992). No obvious and significant hydrogen uptake was measured in any of the materials after testing at room temperature. However, as expected, significant hydrogen uptake was measured for the specimens tested at 800 ° C for both AM and hot rolled materials.