Issue 46

I. Čamagić et alii, Frattura ed Integrità Strutturale, 46 (2018) 371-382; DOI: 10.3221/IGF-ESIS.46.34 379 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]. 0 100 200 300 400 500 600 0 40 80 120 160 200 Weld metal - WM Fracture toughness, K Ic , MPa m 1/2 Testing temperature, o C 0 100 200 300 400 500 600 0 10 20 30 40 50 Weld metal - WM Critical crack length, a c , mm Testing temperature, o C Figure 9 : Changes in value of K Ic depending on the testing temperature for the WM (left) and change in value of a c (right). 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]. Specimen mark Testing temperature,  C Critical J-integral, J Ic , kJ/m 2 Critical stress intensity factor, K Ic , MPa m 1/2 Critical crack length, a c , mm HAZ-1-1n 20 53.6 111.2 34.3 HAZ-1-2n 51.7 109.2 33.0 HAZ-1-3n 49.8 107.2 31.8 HAZ-2-1n 540 33.6 76.9 31.1 HAZ-2-2n 34.2 77.5 31.6 HAZ-2-3n 36.1 79.7 33.4 Table 11 : Values of, K Ic notched specimens at new HAZ. Specimen mark Testing temperature,  C Critical J-integral, J Ic , kJ/m 2 Critical stress intensity factor, K Ic , MPa m 1/2 Critical crack length, a c , mm HAZ-1-1e 20 42.4 96.3 32.0 HAZ-1-2e 36.1 91.3 31.5 HAZ-1-3e 35.6 90.6 31.1 HAZ-2-1e 540 20.2 59.6 25.4 HAZ-2-2e 22.5 62.9 28.3 HAZ-2-3e 21.7 61.8 27.3 Table 12 : Values of, K Ic notched specimens at exploited HAZ.