PSI - Issue 14

Priti Kotak Shah et al. / Procedia Structural Integrity 14 (2019) 242–250 Priti et. al. / Structural Integrity Procedia 00 (2018) 000–000

248

7

800

700

600

500

J (kJ/m 2 )

400

300

200

300 0 C Test Axial notch Transverse notch

100

0

0

0.5

1

1.5

2

2.5

del a (mm)

Fig. 10. J vs a plot for axial and transverse notched specimens at 300 0 C .

300

250

200

150 Ji (kJ/m 2 )

100

50

J i Axial J i Transverse

0

0

50

100 150 200 250 300

Temp ( o C)

0 C for axial and transverse notched specimens.

Fig. 11. Variation of initiation toughness parameter ( J i ) between RT to 300

fore dJ da values show increase w.r.t temperature for axial notched specimens. For transverse crack growth it remains largely flattish. Similar type of e ff ect i.e temperature having stronger influence in raising the fracture toughness in the axial notched specimen than in transverse notched specimens, has also been observed by F. H. Huang in Zircaloy.

3. Conclusions

1. Fracture toughness of Zr-2.5Nb pressure tube has been characterized along axial and circumferential crack growth directions at di ff erent test temperature. 2. In general, toughness for axial crack growth direction is higher than the circumferential crack growth. How ever, at ambient temperature both the orientations show similar crack initiation toughness levels & crack growth resistance.