PSI - Issue 68

Marcell Gáspár et al. / Procedia Structural Integrity 68 (2025) 500–505 M. Gáspár et al. / Structural Integrity Procedia 00 (2025) 000–000

504

5

Fig. 6. Failure modes of the tested samples of the original weld metal (a), CGHAZ-W (b) and ICHAZ-W (c). Failure modes are according to EN ISO 14556.

Force-displacement diagrams of chosen test samples are presented in Fig. 6. It is evident that the failure mode in the original weld metal and in CGHAZ-W was ductile. On the other hand, instable crack propagation was observed in ICHAZ-W. Detailed numerical values of the test results are provided in Table 2.

Table 2. Instrumented CVN results.

Zone

T max [°C]

t 8/5 [s]

F max [kN] 22.7 26.5 24.8 23.3 24.2 23.9 23.1

e [mm]

CVN [J] 183.4 164.1 183.1 178.3 153.8 146.8 124.7

W i [J]

W ic [%] 30.6 34.4 33.9 37.5 38.9 46.2 37.7

W p [J]

W pc [%] 69.4 65.6 66.1 62.5 61.1 53.8 57.3

Fracture mode

BM

-

-

2.23 1.93 2.02 2.14 1.80 1.83 1.65

55.5 56.4 62.0 66.9 59.3 67.1 54.2

126.7 107.6 121.0 113.4

mostly ductile mostly ductile mostly ductile

CGHAZ-W CGHAZ-W CGHAZ-W ICHAZ-W ICHAZ-W ICHAZ-W

1350 1350 1350

5

15 30

little instable crack propagation little instable crack propagation

815 815 815

5

94.6 79.7 72.9

15 30

ductile-brittle ductile-brittle

4. Conclusions Physical simulation was performed by Gleeble 3500 thermomechanical simulator to produce HAZs on the pre existing weld metal joining two pieces of a 16 mm thick 500 MPa offshore steel. The studied simulated HAZ regions included intercritical (ICHAZ-W) and coarse-grained HAZ of the weld (CGHAZ-W) with three different cooling