PSI - Issue 60

B Shashank Dutt et al. / Procedia Structural Integrity 60 (2024) 690–699 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

696

7

300

SA 333 steel (Kamat, 2011 ) P91 steel (Samant, 2020 ) P91 steel P91 steel (Dutt, 2011) P91 steel (Stratil, 2017)

0.5

250

200 Estimated K 1c , MPa.m

150

150

200

250

300

350

Experimental K j1c , MPa.m 0.5

Fig.4. Estimated K 1c and Determined fracture toughness

Estimation of K 1c was carried out for P91 steels, subjected to various thermo-mechanical treatments by Samant et al. (2020). Estimated K 1c values were within 2-16% of the determined Kj 1c values (Table 6). Results of estimated K 1c for P91 steels (Stratil et al. 2017) from a different investigation were included in Table 7. For SA 333 type of steels (Kamat et al. 2011), estimated K 1c were within 11-35% of the determined values (Table 8). From Table 8, it is observed that for only one test (175 °C) temperature (out of six), difference between estimated K 1c and determined fracture toughness was greater than 30 % (35 %).

Table 4. Estimated K 1c results of P91 steels

Test temperature (°C)

Estimated Modulus of toughness (MJ.m -3 )

Estimated K 1c ( MPa. m

0.5 )

Determined K

j1c ( MPa. m

0.5 )

Percentage difference (%)

300

81

186

227

17

350

62

162

228

28

400

73

174

203

14

450

74

173

198

12

500

108

207

223

7

550

112

206

237

12