PSI - Issue 14

Hari Krishan Yadav et al. / Procedia Structural Integrity 14 (2019) 605–611 Hari Krishan Yadav/ Structural Integrity Procedia 00 (2018) 000–000

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Table 3. Rupture life, minimum creep rate, % area reduction and % rupture elongation of various cold worked samples. Cold work Stress (MPa) Rupture life (hrs) Minimum creep rate (h -1 ) % Rupture elongation

CW0 CW1 CW2 CW3 CW4

155 2683 3091 2017 1470

3.9E-04 8.18E-06 6.5E-06 1.01E-05 1.89E-05

18.57 10.28 8.02 6.25 13.6

200

Fig. 4. (a) Strain vs rupture life; (b) strain rate vs rupture life of creep tested samples

Fig. 5. Creep rupture life of various cold worked samples

3.3. Microstructural evolution during creep Optical micrographs of crept samples are shown in Fig. 6. Optical micrographs of CW0 sample revealed almost homogeneous microstructure and there were no sign of recrystallization. On the other hand, complex microstructure was observed in cold worked samples.