PSI - Issue 33

Wei Song et al. / Procedia Structural Integrity 33 (2021) 802–808 Author name / Structural Integrity Procedia 00 (2019) 000–000

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(2) The FCGR of BM and weldments have been examined under as-welded and PWHT states. Dur to the existing of the residual stress in extracted CT specimens, it shows noticeably differences of FCGR between E-WM and U WM. Noted that the FCGR in the as-welded state is lower than in the PWHT state considering the effect of compressive residual stresses. As for the U-WM specimens at R=0.1 and 0.4, FCGR under the as-welded state is slightly lower than PWHT state, attributing to the tensile residual stress effect on fatigue crack tip.

(a)

(b)

10 -4

10 -4

BM E-WM U-WM

BM E-WM U-WM

BS7910 for BM

BS7910 for BM

10 -5

10 -5

BS7910 for WM

10 -6

10 -6

10 -7

BS7910 for WM

10 -7

da/dN (m/cycle)

da/dN (m/cycle)

R=0.1

R=0.4

10 -8

10 -8

30

40

50

60 70 80 90 100

30

40

50

60 70 80 90 100

 K (MPaꞏm 1/2 )

 K (MPaꞏm 1/2 )

(d)

(c)

10 -4

10 -4

BM E-WM U-WM

BM E-WM U-WM

R=0.1 R=0.4 R=0.7

BS7910 for BM

10 -5

10 -5

BS7910 for BM

10 -6

10 -6

BS7910 for WM

BS7910 for WM

R=0.1

10 -7

10 -7

R=0.4

da/dN (m/cycle)

da/dN (m/cycle)

R=0.7

R=0.7

10 -8

10 -8

10

20

30 40 50 60 70 80 90

100

10

20

30 40 50 60 70 80 90

100

 K (MPaꞏm 1/2 )

 K (MPaꞏm 1/2 )

Fig. 5. Effect of stress ratio on the FCGR of 10CrNi3MoV steel and its weldments under PWHT by comparison with standard codes: (a) R=0.1; (b) R=0.4; (c) R=0.7; (d) Summary for different stress ratio. Acknowledgements The research project is supported by the Natural Science Foundation of Jiangsu Province (grant no. BK20200174), the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (grant no. 20KJB430008), and the Qinglan project of Jiangsu province. References Dwivedi, S.K., Vishwakarma, M., 2019. Effect of hydrogen in advanced high strength steel materials, International Journal of Hydrogen Energy. 44, 28007-28030. Hoyos, J.J., Masoumi, M., Pereira, V.F., Tschiptschin, A.P., Paes, M.T.P., Avila, J.A., 2019. Influence of hydrogen on the microstructure and fracture toughness of friction stir welded plates of API 5L X80 pipeline steel. International Journal of Hydrogen Energy 44, 23458-23471. Liu, Q., Zhou, Q., Venezuela , J., Zhang, M., Wang, J., Atrens, A., 2016. A review of the influence of hydrogen on the mechanical properties of DP, TRIP, and TWIP advanced high-strength steels for auto construction. Corrosion Reviews 34, 127-152. Mehmanparast, A., Brennan, F., Tavares, I., 2017. Fatigue crack growth rates for offshore wind monopile weldments in air and seawater: SLIC inter-laboratory test results. Materials & Design 114, 494-504.