Chaper 5 Graphitization and J IC
5.5 Future research
5.5.2 SP testing improvements
Some work has been done in the field of small punch testing to achieve the crack initiation information with greater certainty. There remains potential for improved and innovative means of obtaining such parameters which plays a critical role in the test method.
Testing samples at elevated as well as cryogenic temperatures is a potentially vital addition to this study thereby enabling the study of specimens at temperatures of service.
A great deal of simulation effort is expended in the highly iterative process involved in this method. As more and more work is carried out in this field the database of simulation SP load displacement curves grows. A method to automate the process of filtering the database and providing, at a minimum, a suggested set of close fit Ramberg Osgood parameters would be a helpful addition to the test mechanism.
Sectioned core micrograph showing graphitization.
Virtual section of the x-ray tomography core showing
graphite visualization
References
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Appendix A
Appendix A Results of SP testing on Service Exposed ASTM A-515 Gr. 65
Results of SP testing on Service Exposed ASTM
A-515 Gr. 65
Figure A-1: Results of group 1 graphitization specimen W17_Sample I-11, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched macrograph of
the effective test area with the location where crack initiation occurred.
W17_Sample I-11 Critical crack initiation properties Graphitization quantity [%] 0.1544
Classification group 1
Radial location [mm] 0.76
Initiation force [N] 906
Initiation displacement [mm] 0.7825 Critical Strain Energy density
wSP [MJ/m3] 202.496
Estimated JIC [kJ/m2] 190.84
Ramberg Osgood D=920, n=3.95,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-2: Results of group 1 graphitization specimen W17_Sample C-15, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-15 Critical crack initiation properties Graphitization quantity [%] 0.1755
Classification group 1
Radial location [mm] 0.7
Initiation force [N] 915
Initiation displacement [mm] 0.895 Critical Strain Energy density
wSP [MJ/m3] 233.37
Estimated JIC [kJ/m2] 214.67
Ramberg Osgood D=990, n=3.8,
YS=200
t = 0 sec
i ii
iii 1mm
Figure A-3: Results of group 1 graphitization specimen W17_Sample C-9, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched macrograph of
the effective test area with the location where crack initiation occurred.
W17_Sample C-9 Critical crack initiation properties Graphitization quantity [%] 0.1767
Classification group 1
Radial location [mm] 0.642
Initiation force [N] 1098
Initiation displacement [mm] 1.195 Critical Strain Energy density
wSP [MJ/m3] 341.7
Estimated JIC [kJ/m2] 589
Ramberg Osgood D=820, n=5,
YS=255
t = 0 sec
i ii
iii 1mm
Figure A-4: Results of group 1 graphitization specimen W17_Sample C-13, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-13 Critical crack initiation properties Graphitization quantity [%] 0.1881
Classification group 1
Radial location [mm] 0.7
Initiation force [N] 993
Initiation displacement [mm] 1.005 Critical Strain Energy density
wSP [MJ/m3] 278.104
Estimated JIC [kJ/m2] 394.715
Ramberg Osgood D=900, n=4.2,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-5: Results of group 1 graphitization specimen W17_Sample C-17, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-17 Critical crack initiation properties Graphitization quantity [%] 0.1981
Classification group 1
Radial location [mm] 0.7
Initiation force [N] 876
Initiation displacement [mm] 0.8875 Critical Strain Energy density
wSP [MJ/m3] 223.37
Estimated JIC [kJ/m2] 231.6
Ramberg Osgood D=930, n=4,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-6: Results of group 1 graphitization specimen W17_Sample C-18, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-18 Critical crack initiation properties Graphitization quantity [%] 0.2150
Classification group 1
Radial location [mm] 0.7
Initiation force [N] 966
Initiation displacement [mm] 0.9325 Critical Strain Energy density
wSP [MJ/m3] 201.94
Estimated JIC [kJ/m2] 177.41
Ramberg Osgood D=985, n=3.9,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-7: Results of group 1 graphitization specimen W17_Sample C-12, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-12 Critical crack initiation properties Graphitization quantity [%] 0.2603
Classification group 1
Radial location [mm] 0.7
Initiation force [N] 891
Initiation displacement [mm] 0.91 Critical Strain Energy density
wSP [MJ/m3] 235.79
Estimated JIC [kJ/m2] 263.7
Ramberg Osgood D=890, n=4.2,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-8: Results of group 1 graphitization specimen W17_Sample I-10, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched macrograph of
the effective test area with the location where crack initiation occurred.
W17_Sample I-10 Critical crack initiation properties Graphitization quantity [%] 0.2638
Classification group 1
Radial location [mm] 0.72
Initiation force [N] 823.5
Initiation displacement [mm] 0.8775 Critical Strain Energy density
wSP [MJ/m3] 201.67
Estimated JIC [kJ/m2] 196.71
Ramberg Osgood D=860, n=4.2,
YS=170
t = 0 sec
i ii
iii 1mm
Figure A-9: Results of group 1 graphitization specimen W17_Sample I-12, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched macrograph of
the effective test area with the location where crack initiation occurred.
W17_Sample I-12 Critical crack initiation properties Graphitization quantity [%] 0.2775
Classification group 1
Radial location [mm] 0.6
Initiation force [N] 805.5
Initiation displacement [mm] 0.8725 Critical Strain Energy density
wSP [MJ/m3] 245.67
Estimated JIC [kJ/m2] 320.51
Ramberg Osgood D=845, n=4.2,
YS=170
t = 0 sec
i ii
iii 1mm
Figure A-10: Results of group 1 graphitization specimen W17_Sample D-10, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample D-10 Critical crack initiation properties Graphitization quantity [%] 0.2784
Classification group 1
Radial location [mm] 0.5
Initiation force [N] 905
Initiation displacement [mm] 0.9175 Critical Strain Energy density
wSP [MJ/m3] 272.99
Estimated JIC [kJ/m2] 375.8
Ramberg Osgood D=850, n=4.7,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-11: Results of group 1 graphitization specimen W17_Sample C-5, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-5 Critical crack initiation properties
Graphitization quantity [%] 0.3683
Classification group 2
Radial location [mm] 0.8
Initiation force [N] 837
Initiation displacement [mm] 0.8725 Critical Strain Energy density
wSP [MJ/m3] 149.88
Estimated JIC [kJ/m2] 89.60
Ramberg Osgood D=810, n=5,
YS=255
t = 0 sec
i ii
iii 1mm
Figure A-12: Results of group 1 graphitization specimen W17_Sample C-16, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-16 Critical crack initiation properties Graphitization quantity [%] 0.3875
Classification group 2
Radial location [mm] 0.7
Initiation force [N] 828
Initiation displacement [mm] 0.855 Critical Strain Energy density
wSP [MJ/m3] 203.09
Estimated JIC [kJ/m2] 189.49
Ramberg Osgood D=920, n=3.95,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-13: Results of group 1 graphitization specimen W17_Sample C-14, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-14 Critical crack initiation properties
Graphitization quantity [%] 0.4223
Classification group 2
Radial location [mm] 0.78
Initiation force [N] 666
Initiation displacement [mm] 0.665 Critical Strain Energy density
wSP [MJ/m3] 86.04
Estimated JIC [kJ/m2] 40.55
Ramberg Osgood D=985, n=3.9,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-14: Results of group 1 graphitization specimen W17_Sample C-8, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-8 Critical crack initiation properties Graphitization quantity [%] 0.4399
Classification group 2
Radial location [mm] 0.8
Initiation force [N] 699
Initiation displacement [mm] 0.7125 Critical Strain Energy density
wSP [MJ/m3] 91.46
Estimated JIC [kJ/m2] 37.56
Ramberg Osgood D=800, n=5.25,
YS=270
t = 0 sec
i ii
iii 1mm
Figure A-15: Results of group 1 graphitization specimen W17_Sample I-7, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched macrograph of
the effective test area with the location where crack initiation occurred.
W17_Sample I-7 Critical crack initiation properties
Graphitization quantity [%] 0.4527
Classification group 2
Radial location [mm] 0.7
Initiation force [N] 670.5
Initiation displacement [mm] 0.710 Critical Strain Energy density
wSP [MJ/m3] 127.73
Estimated JIC [kJ/m2] 77.29
Ramberg Osgood D=830, n=4.6,
YS=170
t = 0 sec
i ii
iii 1mm
Figure A-16: Results of group 1 graphitization specimen W17_Sample C-11, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-11 Critical crack initiation properties Graphitization quantity [%] 0.6584
Classification group 3
Radial location [mm] 0.7
Initiation force [N] 693
Initiation displacement [mm] 0.725 Critical Strain Energy density
wSP [MJ/m3] 133.94
Estimated JIC [kJ/m2] 83.85
Ramberg Osgood D=890, n=4.2,
YS=180
t = 0 sec
i ii
iii 1mm
Figure A-17: Results of group 1 graphitization specimen W17_Sample C-7, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-7 Critical crack initiation properties Graphitization quantity [%] 0.9170
Classification group 3
Radial location [mm] 0.8
Initiation force [N] 691.5
Initiation displacement [mm] 0.72 Critical Strain Energy density
wSP [MJ/m3] 95.34
Estimated JIC [kJ/m2] 42.57
Ramberg Osgood D=810, n=5,
YS=255
t = 0 sec
i ii
iii 1mm
Figure A-18: Results of group 1 graphitization specimen W17_Sample D-7, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample D-7 Critical crack initiation properties Graphitization quantity [%] 0.9933
Classification group 3
Radial location [mm] 0.16
Initiation force [N] 253
Initiation displacement [mm] 0.151 Critical Strain Energy density
wSP [MJ/m3] 62.93
Estimated JIC [kJ/m2] 22.85
Ramberg Osgood D=810, n=5,
YS=200
t = 0 sec
i ii
iii 1mm
Figure A-19: Results of group 1 graphitization specimen W17_Sample C-6, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample C-6 Critical crack initiation properties Graphitization quantity [%] 1.4698
Classification group 3
Radial location [mm] 0.78
Initiation force [N] 642.5
Initiation displacement [mm] 0.685 Critical Strain Energy density
wSP [MJ/m3] 80.843
Estimated JIC [kJ/m2] 32.01
Ramberg Osgood D=770, n=5.2,
YS=265
t = 0 sec
i ii
iii 1mm
Figure A-20: Results of group 1 graphitization specimen W17_Sample D-8, i) sample shown in test fixture prior to the start of testing, ii) sample shown in test fixture at time of crack initiation and iii) un-etched
macrograph of the effective test area with the location where crack initiation occurred.
W17_Sample D-8 Critical crack initiation properties Graphitization quantity [%] 1.7528
Classification group 3
Radial location [mm] 0.55
Initiation force [N] 390
Initiation displacement [mm] 0.3585 Critical Strain Energy density
wSP [MJ/m3] 51.38
Estimated JIC [kJ/m2] 18.64
Ramberg Osgood D=860, n=4.6,
YS=170
t = 0 sec
i ii
iii 1mm
Appendix B
Appendix B Graphical Results of SP testing on Service Exposed ASTM A-515 Gr. 65
Graphical Results of SP testing on Service
Exposed ASTM A-515 Gr. 65
Figure B-1: Graphs of all samples tested in order of ascending percentage graphitization.