Search
Filters

51316-7183-Sour Service Fatigue and Fracture Behavior of High Strength Steels

Fatigue Crack Growth Rate (FCGR) and fracture toughness behavior of high strength steels used in drilling riser applications was investigated in sour environments. Frequency scan tests were performed were performed on X80 C110 and S135 in moderate to mildly sour environments.

Product Number: 51316-7183-SG
ISBN: 7183 2016 CP
Author: Thodla Ramgopal
Publication Date: 2016
$0.00
$20.00
$20.00

Fatigue Crack Growth Rate (FCGR) and fracture toughness behavior of high strength steels used in drilling riser applications was investigated in sour environments. Frequency scan tests were performed were performed on X80 C110 and S135 in moderate to mildly sour environments. Fatigue crack growth rate increased with decreasing frequency and reached a plateau value at look frequencies. The observed behavior is typical for hydrogen enhanced cracking in sour environment. At these “plateau frequencies” FCGR in the mildly sour environments were found to be about 10 to 30x higher than the in-air values. The rate controlling step for FCGR was found to be hydrogen diffusion through the fracture process zone. The critical concentration for crack advance was calculated based on a model based on hydrogen diffusion through the fracture process zone. The critical concentration of hydrogen for S-135 was significantly lower than C-110 and X-80. The critical concentration of hydrogen for crack advance for C-110 and X-80 were similar.Rising-displacement FT tests were performed in a range of environments to determine the resistance (R-curve) behavior. Tests were performed in-situ at a slow K rate of 0.05Nmm-3/2/s over a range of environmental conditions as well as microstructures namely S-135 C-110 X-80. The results show that the initiation toughness and the slope of the R-curve decreased sharply in the sour environments. A limited set of tests were performed on a 110ksi grade steel in hydrogen charged conditions to discern the effect of loading rate format and develop a mechanistic interpretation for observed J-R curve behavior.

Fatigue downloadable, Crack Growth, fracture toughness, hydrogen, sour environments, microstructure

Fatigue Crack Growth Rate (FCGR) and fracture toughness behavior of high strength steels used in drilling riser applications was investigated in sour environments. Frequency scan tests were performed were performed on X80 C110 and S135 in moderate to mildly sour environments. Fatigue crack growth rate increased with decreasing frequency and reached a plateau value at look frequencies. The observed behavior is typical for hydrogen enhanced cracking in sour environment. At these “plateau frequencies” FCGR in the mildly sour environments were found to be about 10 to 30x higher than the in-air values. The rate controlling step for FCGR was found to be hydrogen diffusion through the fracture process zone. The critical concentration for crack advance was calculated based on a model based on hydrogen diffusion through the fracture process zone. The critical concentration of hydrogen for S-135 was significantly lower than C-110 and X-80. The critical concentration of hydrogen for crack advance for C-110 and X-80 were similar.Rising-displacement FT tests were performed in a range of environments to determine the resistance (R-curve) behavior. Tests were performed in-situ at a slow K rate of 0.05Nmm-3/2/s over a range of environmental conditions as well as microstructures namely S-135 C-110 X-80. The results show that the initiation toughness and the slope of the R-curve decreased sharply in the sour environments. A limited set of tests were performed on a 110ksi grade steel in hydrogen charged conditions to discern the effect of loading rate format and develop a mechanistic interpretation for observed J-R curve behavior.

Fatigue downloadable, Crack Growth, fracture toughness, hydrogen, sour environments, microstructure

Also Purchased
Picture for Effect of H2S and CO2 on Fatigue Corrosion Crack Growth and Fracture Toughness of X65 in Offshore Oi
Available for download

51312-01577-Effect of H2S and CO2 on Fatigue Corrosion Crack Growth and Fracture Toughness of X65 in Offshore Oi

Product Number: 51312-01577-SG
ISBN: 01577 2012 CP
Author: Feng Gui
Publication Date: 2012
$20.00
Picture for 03112 FITNESS FOR PURPOSE EVALUATION
Available for download

03112 FITNESS FOR PURPOSE EVALUATION OF SOUR SERVICE RISER PIPES

Product Number: 51300-03112-SG
ISBN: 03112 2003 CP
Author: Curt Christensen, Hans Peter Nielsen, Ragnar Mollan
$20.00
Picture for 00139 FIT-FOR-PURPOSE MATERIALS TESTING FOR
Available for download

00139 FIT-FOR-PURPOSE MATERIALS TESTING FOR SOUR GAS SERVICE

Product Number: 51300-00139-SG
ISBN: 00139 2000 CP
Author: M. G. Hay
$20.00