Crack Paths 2009

3

2

2

10 µ m

10 µ m

10 µ m

10 m

4

1

4

4

4

1m m 1 m m

3

3

10 µ m

10 µ m

Figure6. HIC propagation path through the microstructure.

b)

a)

100 µ m

10 µ m

surface of an early nucleation HICin Plate A. b) Large M n S

Figure 7. a) Fracture

inclusion in the propagation zone.

The Figure 8 shows an early nucleation sites for HIC in plate B, it can be observed

that the area has clusters of M n Sinclusions, while far from the nucleous there were not

nucleated cracks. One cracked area of the Plate B was opened to observe the fracture

surface as shown in Figure 9. This crack was a late one that originated after 192 hrs of

hydrogen charging. As can be observed, this site has a large and isolated M n Sinclusion.

1 m m

Figure 8. Cluster of M n Sinclusions which is an early nucleation site of HIC.

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