Back to Martensitic Stainless Steel
ML00085 - Nov.2017

Corrosion Fatigue of a Martensitic SS Pin

Micrography of the pin in a longitudinal section, transverse to the fracture surface, at the ductile final fracture, presenting microvoids connecting with plastic deformation of the structure.

15

50
of the in a , transverse to the surface, at the ductile final , presenting microvoids connecting with of the .
M

Material

Martensitic Stainless Steel
  • UNS S43100 mod
Ds

Description

The swivel broke when it was operating in a system for supporting stored . The failure mechanism is and occurred because the pin was cyclically bent and the passive layer broke intermittently, creating multiple surface that propagated by . The final rupture was ductile by .

C

Chemistry (% in weight)

Pin analysis

0.034C; 0.45Si; 0.88Mn; 0.032P; 0.009S; 15.5Cr; 5.2Ni; 0.34Cu.

Associated Images
Microscopic detail of the cracks at the surface of the pin, close to the fracture. It is possible to see that the cracks are not associated to plastic deformation at the surface. Instead they are brittle and associated to regions where the material lost the passivation (dark grey stains at the surface). Some cracks that already opened (a little) showed deformation at the tips.
1024
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface Aspect by SEMDf - Multiple cracks
Low magnification microscopy (stereoscope) detail of the multiple cracks at the pin surface.
146
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Surface AspectDf - Multiple cracks
Aspect of the pin surface, presenting multiple cracks, paralel to the fracture position.
122
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Multiple cracks
Aspect of the 5/8" diameter pin, that was 3" long and broke close to the center.
104
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - General View
Typical fatigue fracture, reversed bending.
74
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Aspect Before AnalysisDf - Fracture
The fractographic analysis of the pin showed fatigue striation at the subcritical propagation region.
75
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Fractography by SEMDf - Fatigue Striation
The fractographic analysis of the pin showed ductile final fracture, by dimples.
76
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Fractography by SEMDf - Dimples
Micrography of the pin microstructure at the longitudinal section showing a tempered martensitic structure and a band of retained austenite.
60
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Martensite
Micrographic detail of the pin microstructure at the longitudinal section showing a tempered martensitic structure and a band of retained austenite.
61
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Banded Structure
Micrographic detail of the pin microstructure at the longitudinal section showing a band of retained austenite in martensitic structure.
58
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Martensite
Micrography of the pin in a longitudinal section, transverse to the fracture surface, close to the point of cracking iniciation, presenting a flat propagation and a secondary crack, paralel to the fracture surface.
54
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fracture
Micrography of the pin in a longitudinal section, transverse to the fracture surface, close to the point of cracking iniciation, presenting a flat propagation and a secondary crack, paralel to the fracture surface.
52
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fracture
Micrographic detail of a secondary cracking close to the fracture position. The crack presents no plastic deformation, is slightly branched and filled with products.
52
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fatigue Fracture
Micrography of the pin in a longitudinal section, transverse to the fracture surface, at the ductile final fracture, presenting a rough propagation.
44
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Fracture
Micrography of the pin in a longitudinal section, transverse to the fracture surface, at the ductile final fracture, presenting microvoids connecting with plastic deformation of the structure.
50
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Micrography by OMDf - Fracture
Micrographic detail of the pin in a longitudinal section, transverse to the fracture surface, at the ductile final fracture, presenting microvoids connecting with plastic deformation of the structure.
41
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Ductile Fracture
Micrography of the pin in a longitudinal section, at the pin surface showing several secondary cracks, without plastic deformation, filled with products and branched.
34
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
Micrography of the pin in a longitudinal section, at the pin surface showing several secondary cracks, without plastic deformation, filled with products and branched.
35
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks
Micrography of the pin in a longitudinal section, at the pin surface showing a secondary crack, without plastic deformation, filled with products and branched.
35
VIEW
ML00085 / Nov.2017
Corrosion Fatigue of a Martensitic SS Pin
M - Martensitic Stainless SteelP - Forged PinAp - O&G Well DrillingCd - Corrosion Fatigue
Cm - Kalling Etched Micrography by OMDf - Secondary Cracks