Issue 46

I. Čamagić et alii, Frattura ed Integrità Strutturale, 46 (2018) 371-382; DOI: 10.3221/IGF-ESIS.46.34

Impact of the testing temperature on the value of critical stress intensity factor, K Ic , for notched specimens in WM is graphically illustrated in Fig. 9 (left), and the impact of the testing temperature on the value of the critical crack length, a c , is graphically illustrated in Fig. 9, (right) [1].

50

200

Weld metal - WM

Weld metal - WM

40

160

120 Ic , MPa m 1/2

c , mm

30

20

80

10

40

Critical crack length, a

Fracture toughness, K

0

0

0

100

200

300

400

500

600

0

100

200

300

400

500

600

Testing temperature, o C

Testing temperature, o C

depending on the testing temperature for the WM (left) and change in value of a c (right).

Figure 9 : Changes in value of K Ic

Calculated values of critical stress intensity factor, K Ic , and critical crack length, ac, are given in the Tab. 11 for notched specimens in HAZ from the side of the new PM and in Tab. 12 for notched specimens in HAZ from the side of the exploited PM, tested at room temperature of 20  C and working temperature of 540  C, [1].

Testing temperature,  C

Specimen mark HAZ-1-1n HAZ-1-2n HAZ-1-3n HAZ-2-1n HAZ-2-2n HAZ-2-3n

Critical J-integral, J Ic , kJ/m 2

Critical stress intensity factor, K Ic , MPa m 1/2

Critical crack length, a c , mm

53.6 51.7 49.8 33.6 34.2 36.1

111.2 109.2 107.2

34.3 33.0 31.8 31.1 31.6 33.4

20

76.9 77.5 79.7

540

Table 11 : Values of, K Ic

notched specimens at new HAZ.

Testing temperature,  C

Specimen mark HAZ-1-1e HAZ-1-2e HAZ-1-3e HAZ-2-1e HAZ-2-2e HAZ-2-3e

Critical J-integral, J Ic , kJ/m 2

Critical stress intensity factor, K Ic , MPa m 1/2

Critical crack length, a c , mm

42.4 36.1 35.6 20.2 22.5 21.7

96.3 91.3 90.6 59.6 62.9 61.8

32.0 31.5 31.1 25.4 28.3 27.3

20

540

Table 12 : Values of, K Ic

notched specimens at exploited HAZ.

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