Back to Low Alloy Medium Carbon QT
ML00088 - Dec.2017

Hydrogen Cracking of an API 5D S135 Drill Pipe

Aspect of the fracture surface of the pin, still assembled in the box (that is externally to the pin). The pin fracture is flat, presenting radial marks.

1

791
Aspect of the surface of the , still assembled in the box (that is externally to the ). The is flat, presenting radial marks.
M

Material

Low Alloy Medium Carbon QT
  • API 5D S135
Ds

Description

The column, that was in service during less than one year, broke during its own handling (weight only) in environment, temperatures between 4°C and 20°C. The occurred in the side of the tool joint. The high strength material presented high toughness properties at low temperature and the showed intergranular and transgranular (quasecleavage) characteristics, associated to conditions due to subsea service.

C

Chemistry (% in weight)

Pin Analysis

0.36C; 0.27Si; 0.96Mn; 0.011P; 0.008S; 1.07Cr; 0.12Ni; 0.32Mo.

Associated Images
Aspect of the fracture surface of the pin, still assembled in the box (that is externally to the pin). The pin fracture is flat, presenting radial marks.
791
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect Before AnalysisDf - Brittle Fracture
Micrographic detail of the quenched and tempered martensitic structure of the pin tool joint.
83
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Martensite
Macrography of the longitudinal section of the tool joint, assembled. The pin is still attached to the box end of the other drill pipe in the column, showing that the pin fractured in the region of external diameter transition (right side of the figure), where the box was probably touching the pin shoulder. Interesting to note that the inner diameter still presents a sound coating.
73
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Longitudinal Section AspectDf - Longitudinal Section
Visual aspect of the tool joint (TJ) that fractured in the pin body when it was assembled (the box appears as a sleeve in the pin OD). The internal coating is not damaged. The fracture is flat and presents little evidences of plastic deformation, indicating that the pin broke in a brittle way.
69
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Aspect by NDTDf - Brittle Fracture
Detail of the flat fracture surface of the pin, after disassembling from the TJ box. ID in the top and OD in the bottom of the figure. Radial marks are clear in the fracture surface.
57
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Fracture Surface AspectDf - Brittle Fracture
Fractographic analysis of the pin fracture surface showing inter and transgranular morphologies of fracture micromechanisms.
53
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Fractography by SEMDf - Brittle Fracture
Fractographic analysis of the pin showing several secondary intergranular cracks (in the middle of the figure) and quasecleavage transgranular fracture mechanism.
45
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Surface Aspect by SEMDf - Brittle Fracture
Fractographic analysis of the pin detailing a region of predominantly quasecleavage fracture micromechanism, associated to a macroscopic flat fracture surface.
46
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Surface Aspect by SEMDf - Cleavage Facets
Fractographic analysis of the pin showing a region of predominantly intergranular fracture micromechanism.
46
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Surface Aspect by SEMDf - Intergranular Cracking
Micrography of the pin longitudinal section (transverse to the fracture), in low magnification, close to the external surface of the pin (right side of the figure). The fracture (in the top of the figure) is flat, also evidencing no plastic deformation.
41
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography of the pin longitudinal section (transverse to the fracture), as polished. The fracture (in the top of the figure) is flat and it is possible to see secondary cracks with intergranular morphology.
40
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Micrography by OMDf - Secondary Cracks
Micrographic detail of a secondary intergranular cracking at the pin longitudinal section (transverse to the fracture).
38
VIEW
ML00088 / Dec.2017
Hydrogen Cracking of an API 5D S135 Drill Pipe
M - Low Alloy Medium Carbon QTP - Drill PipeAp - SubseaCd - Hydrogen Embrittlement
Cm - Nital Etched Micrography by OMDf - Intergranular Cracking