Step 8 · Diagnose
Adaptive diagnosis
The engine scores the candidate failure modes from your evidence and asks the single question
that best separates the ones still in contention — repeating until one mode reaches high confidence or the
candidates are exhausted. Every step is driven by the knowledge pack: deterministic and explainable.
i
Confidence — evidence support for this mode. This is the strength of the entered evidence in support of this failure mode. It is NOT a probability, a statistical likelihood, or a finding of fact.
High strong support
Moderate partial; key confirmation missing
Low weak / little support
· 0 adaptive answer(s) recorded
✓ Diagnosis converged
Thermal-mechanical fatigue has reached high confidence.
Shortlisted failure modes · from the material-filtered cards · adaptive workspace
The Failure-Mode Cards whose indicators your evidence matches — these are what the
questions above are discriminating between. The full scored landscape (all families) is below.
Thermal-mechanical fatigue leading
Fatigue cracking caused by cyclic thermal strain, often with constraint and mechanical loading.
Supporting evidence present
- Network or surface cracks (critical)
- crack orientation related to thermal stress
- service temperature cycles
Evidence missing
- oxide-filled cracks (Corrosion products / deposits)
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination
- Operating-condition review
- Corrosion-product analysis (EDS/XRD)
Explain this score (raw S / K / C / M / B)
S=0.8 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Fretting fatigue cracking
Fatigue cracking promoted by small-amplitude oscillatory contact slip at a stressed interface.
Supporting evidence present
- Dark fretting debris (critical)
- contact scar
- crack at contact edge
Evidence missing
- multiple shallow origins (Macro / visual examination)
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Loading / stress review
Explain this score (raw S / K / C / M / B)
S=0.8 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Bending fatigue
Fatigue driven by cyclic bending stress, often with tensile surface origin.
Supporting evidence present
- Semi-elliptical surface origin (critical)
- crack front marks
Evidence missing
- final overload opposite origin (Macro / visual examination)
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
Explain this score (raw S / K / C / M / B)
S=0.75 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Ammonia SCC
SCC associated with ammonia/ammoniacal environments in susceptible copper alloys and some steels.
Supporting evidence present
- Intergranular/transgranular cracking (critical)
- blue/green corrosion products possible
Evidence missing
- residual stress source (Service environment)
Suggested test to raise certainty
- Service-environment chemistry review or sampling
- SEM fractography
- Corrosion-product analysis (EDS/XRD)
- Environment chemistry review
Explain this score (raw S / K / C / M / B)
S=0.75 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Polythionic acid SCC
SCC of sensitised stainless steels exposed to polythionic acid conditions, often during shutdown.
Supporting evidence present
- Intergranular cracking in sensitised HAZ/base metal (critical)
- refinery shutdown history
Evidence missing
- sulphide/acid conditions (Corrosion products / deposits)
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- SEM fractography
- Macro / visual examination
- Corrosion-product analysis (EDS/XRD)
Explain this score (raw S / K / C / M / B)
S=0.75 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Scuffing / scoring
Severe sliding damage from lubricant film breakdown and local welding/tearing.
Supporting evidence present
- Longitudinal score marks (critical)
- smeared/overheated surfaces
Evidence missing
- rapid damage onset (Macro / visual examination)
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
Explain this score (raw S / K / C / M / B)
S=0.75 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Galling
Severe adhesive wear with macroscopic surface damage and material transfer, often leading to seizure.
Supporting evidence present
- Severe torn surfaces (critical)
- seizure marks
- high friction history
Evidence missing
- transfer lumps (Macro / visual examination)
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
Explain this score (raw S / K / C / M / B)
S=0.7333 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
VHCF
Fatigue failure at very high cycle counts, often from internal defects/inclusions in high-strength alloys.
Supporting evidence present
- Internal fish-eye origin (critical)
- little surface initiation
Evidence missing
- fine granular area (Macro / visual examination)
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography
- Macro / visual examination
Explain this score (raw S / K / C / M / B)
S=0.6667 · K=1.0 · C=0.0 · M=0.0 · B=1.0
S supporting match · K critical coverage · C contradiction penalty · M missing critical · B evidence-base size. Score = 100·S·(0.5+0.5K)·(1−0.7C)·(1−0.4M)·(0.6+0.4B).
Full failure-mode landscape
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All 106 catalogued failure modes are in consideration.
Set the material of the failed component (Material step) to rule out modes that cannot occur for it.
84 show supporting evidence so far.
Every mode is a Failure-Mode Card scored by the confidence model; the 8 calibrated cards are expert-tuned, the rest are AI-drafted and pending expert review.
Mechanical deformation / distortion
8 in play
-
Ratcheting
draft
44.4
Moderate
Supporting evidence present
- Incremental dimensional growth (critical)
- local thinning
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Loading / stress review or analysis
- Dimensional / thickness survey
- Macro / visual examination
- Loading / stress review
-
Plastic collapse
draft
41.7
Moderate
Supporting evidence present
- Gross deformation before rupture (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Loading / stress review or analysis
- Macro / visual examination
- Loading / stress review
-
Necking
draft
29.2
Low
Supporting evidence present
- cup-and-cone fracture association
- dimples if fractured
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- SEM fractography
-
Thermal bowing
draft
17.5
Low
Supporting evidence present
- distortion without cracking
- thermal gradients in service history
Evidence missing
- Repeatable bowing with temperature (Operating conditions)
Suggested test to raise certainty
- Operating-condition data review
- Operating-condition review
- Macro / visual examination
-
Quench/heat-treatment distortion
draft
16.7
Low
Supporting evidence present
- out-of-tolerance dimension
- hardness/microstructure gradients
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Metallography
-
Elastic buckling
draft
5.4
Low
Supporting evidence present
- often little fracture at initiation
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Manufacturing record review
-
General yielding
draft
4.6
Low
Supporting evidence present
- no progressive beach marks
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- SEM fractography
-
Brinelling
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Loading / stress review or analysis
- Macro / visual examination of the fracture and component
- Loading / stress review
- Macro / visual examination
Fracture / rupture
7 in play
-
Torsional shear fracture
draft
53.3
Moderate
Supporting evidence present
- Spiral fracture (critical)
- dimpled shear features
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- SEM fractography
-
Intergranular brittle fracture
draft
mix
41.7
Moderate
Supporting evidence present
- Faceted grain-boundary surface (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Metallographic sectioning and microscopy
- SEM fractography
- Macro / visual examination
- Metallography
-
Dynamic overload fracture
draft
20.0
Low
Supporting evidence present
- Deformation pattern aligned with impact (critical)
- sudden overload features
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Loading / stress review
- Macro / visual examination
-
Ductile overload fracture
calibrated
17.5
Low
Supporting evidence present
- Dimpled (microvoid coalescence) fracture surface under SEM; cup-and-cone profile (critical)
- Documented single overload, impact or pressure surge event
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography of the fracture surface
- Metallographic sectioning and microscopy
- visual/macro
- SEM fractography
-
Pressure burst
draft
10.0
Low
Supporting evidence present
- wall thinning if corrosion-assisted
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Loading / stress review or analysis
- Macro / visual examination
- Loading / stress review
- Dimensional / thickness survey
-
Cleavage fracture
calibrated
9.5
Low
Supporting evidence present
- Chevron (herringbone) marks pointing back to origin
- Impact or high strain-rate loading
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography of the fracture surface
- Operating-condition data review
- Charpy impact
- SEM fractography
-
Stable ductile tearing
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
Fatigue and cyclic cracking
14 in play
-
Fretting fatigue cracking
draft
mix
80.0
High
Supporting evidence present
- Dark fretting debris (critical)
- contact scar
- crack at contact edge
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Loading / stress review
-
Thermal-mechanical fatigue
draft
mix
80.0
High
Supporting evidence present
- Network or surface cracks (critical)
- crack orientation related to thermal stress
- service temperature cycles
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination
- Operating-condition review
- Corrosion-product analysis (EDS/XRD)
-
Bending fatigue
draft
75.0
High
Supporting evidence present
- Semi-elliptical surface origin (critical)
- crack front marks
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
-
VHCF
draft
66.7
Moderate
Supporting evidence present
- Internal fish-eye origin (critical)
- little surface initiation
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography
- Macro / visual examination
-
Low-cycle fatigue
draft
65.0
Moderate
Supporting evidence present
- Multiple crack origins (critical)
- plastic strain marks
- transgranular cracking
- rapid crack growth after cyclic plasticity
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination
- Loading / stress review
-
Weld-toe fatigue
draft
mix
45.0
Moderate
Supporting evidence present
- Crack at weld toe/root (critical)
- beach marks
Evidence missing
- Crack at weld toe/root (Welding records)
Suggested test to raise certainty
- Welding record review
- SEM fractography
-
Torsional fatigue
draft
41.7
Moderate
Supporting evidence present
- Helical or 45-degree crack path (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
-
Resonance-induced fatigue
draft
29.2
Low
Supporting evidence present
- fatigue beach marks
- service vibration history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Loading / stress review or analysis
- Loading / stress review
- SEM fractography
-
High-cycle fatigue
calibrated
27.8
Low
Supporting evidence present
- Beach marks (crack arrest lines) on fracture surface (critical)
- Cyclic/vibratory/rotating service loading (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Macro / visual examination of the fracture and component
- SEM fractography
- macro examination of origin
- stress analysis
-
Corrosion-fatigue cracking
draft
mix
21.7
Low
Supporting evidence present
- Fatigue features with corrosion products (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Axial fatigue
draft
16.7
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Loading / stress review or analysis
- Macro / visual examination of the fracture and component
- Loading / stress review
- SEM fractography
- Macro / visual examination
-
Subsurface rolling-contact fatigue
draft
16.0
Low
Supporting evidence present
- Subsurface origin (critical)
- inclusion-associated crack
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Macro / visual examination
- SEM fractography
-
Surface-initiated rolling-contact fatigue
draft
mix
13.3
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography of the fracture surface
- Macro / visual examination
- SEM fractography
-
Rolling-contact fatigue
draft
6.5
Low
Supporting evidence present
- subsurface or surface-initiated crack networks
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography of the fracture surface
- Macro / visual examination
- SEM fractography
Creep / time-dependent high-temperature damage
7 in play
-
Creep crack initiation/growth
draft
66.7
Moderate
Supporting evidence present
- Intergranular cracking (critical)
- time-dependent crack extension
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- SEM fractography
- Metallography
- Macro / visual examination
-
Primary creep / secondary creep deformation
draft
16.7
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Metallographic sectioning and microscopy
- Macro / visual examination
- Metallography
-
Stress rupture
draft
11.1
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- Macro / visual examination of the fracture and component
- Corrosion-product / deposit analysis (EDS / XRD)
- Metallography
- SEM fractography
-
Creep-fatigue interaction
draft
mix
10.0
Low
Supporting evidence present
- cavities plus fatigue features
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Corrosion-product / deposit analysis (EDS / XRD)
- Service-history record review
- SEM fractography
- Corrosion-product analysis (EDS/XRD)
-
Relaxation failure
draft
10.0
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Loading / stress review or analysis
- Macro / visual examination of the fracture and component
- Loading / stress review
- Macro / visual examination
-
Creep-assisted instability
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Metallographic sectioning and microscopy
- Macro / visual examination
- Metallography
-
Type IV creep cracking
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Welding record review
- SEM fractography
Aqueous / electrochemical corrosion
12 in play
-
Pitting corrosion
calibrated
34.4
Low
Supporting evidence present
- General wall thinning or measurable metal loss (critical)
- Pitting or crevice attack on surfaces (critical)
Evidence missing
- Corrosive service environment (chlorides, acids, moisture, seawater) (Service environment)
Suggested test to raise certainty
- Service-environment chemistry review or sampling
- Corrosion-product / deposit analysis (EDS / XRD)
- Coating / protection system review
- corrosion product analysis
- dimensional/thickness survey
-
Uniform corrosion
draft
23.3
Low
Supporting evidence present
- corrosion products
- predictable corrosion allowance consumption
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / wall-thickness survey
- Dimensional / thickness survey
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Crevice corrosion
draft
16.7
Low
Supporting evidence present
- sharp boundary between exposed
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Bimetallic corrosion
draft
mix
12.5
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Loading / stress review or analysis
- Macro / visual examination of the fracture and component
- Loading / stress review
- Macro / visual examination
-
Under-deposit corrosion
draft
mix
10.0
Low
Supporting evidence present
- chemistry gradient evidence
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
- Chemical composition analysis
-
Atmospheric rusting/corrosion
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
- Coating system review
-
Buried or immersion corrosion
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination
- Corrosion-product analysis (EDS/XRD)
-
CUI
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / wall-thickness survey
- Macro / visual examination of the fracture and component
- Dimensional / thickness survey
- Macro / visual examination
-
DC stray-current corrosion
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / wall-thickness survey
- Macro / visual examination of the fracture and component
- Dimensional / thickness survey
- Macro / visual examination
-
Dealloying
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Chemical composition analysis
-
IGC
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- SEM fractography of the fracture surface
- Macro / visual examination of the fracture and component
- Metallography
- SEM fractography
-
MIC
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
Environmentally assisted cracking and hydrogen damage
12 in play
-
Ammonia SCC
draft
mix
75.0
High
Supporting evidence present
- Intergranular/transgranular cracking (critical)
- blue/green corrosion products possible
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Service-environment chemistry review or sampling
- SEM fractography
- Corrosion-product analysis (EDS/XRD)
- Environment chemistry review
-
Polythionic acid SCC
draft
mix
75.0
High
Supporting evidence present
- Intergranular cracking in sensitised HAZ/base metal (critical)
- refinery shutdown history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- SEM fractography
- Macro / visual examination
- Corrosion-product analysis (EDS/XRD)
-
LME
draft
mix
66.7
Moderate
Supporting evidence present
- Intergranular or brittle crack path (critical)
- rapid cracking during contact
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- SEM fractography
- Macro / visual examination
- Loading / stress review
-
High-temperature hydrogen attack
draft
mix
53.3
Moderate
Supporting evidence present
- Decarburised zones (critical)
- intergranular cracking/blisters
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Metallography
- Macro / visual examination
- SEM fractography
-
Chloride SCC
draft
mix
41.7
Moderate
Supporting evidence present
- Branched transgranular cracks in austenitic stainless steels (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination of the fracture and component
- Metallography
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Stress-oriented HIC
draft
mix
29.2
Low
Supporting evidence present
- crack orientation stress-related
- sour-service history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Loading / stress review
- Environment chemistry review
-
Sulfide stress cracking
draft
mix
15.2
Low
Supporting evidence present
- high hardness/strength
- often little corrosion loss
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Service-environment chemistry review or sampling
- Macro / visual examination
- Hardness survey
- Environment chemistry review
-
Hydrogen-assisted cracking
calibrated
mix
14.3
Low
Supporting evidence present
- Hydrogen source: plating, pickling, cathodic protection, H2S/sour service (critical)
Evidence missing
- Hydrogen source: plating, pickling, cathodic protection, H2S/sour service (Service environment)
Suggested test to raise certainty
- Service-environment chemistry review or sampling
- Material specification & certification review
- SEM fractography of the fracture surface
- Service-history record review
- fractography (intergranular)
-
SCC
calibrated
mix
9.8
Low
Supporting evidence present
- Branched cracking in metallographic section (critical)
Evidence missing
- Susceptible alloy–environment combination present (Service environment)
Suggested test to raise certainty
- Service-environment chemistry review or sampling
- Loading / stress review or analysis
- Metallographic sectioning and microscopy
- metallography (branching)
- SEM
-
Caustic SCC
draft
mix
8.1
Low
Supporting evidence present
- boiler/alkali service history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Corrosion-product / deposit analysis (EDS / XRD)
- SEM fractography
- Corrosion-product analysis (EDS/XRD)
- Service-history review
-
Hydrogen blistering
draft
mix
6.0
Low
Supporting evidence present
- hydrogen/sour/corrosion history
Evidence missing
- Raised blisters (Coating / protection records)
Suggested test to raise certainty
- Coating / protection system review
- Macro / visual examination of the fracture and component
- Coating system review
- Macro / visual examination
- Environment chemistry review
-
Hydrogen-induced cracking
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Coating / protection system review
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination
- Coating system review
Tribology / wear / erosion
12 in play
-
Scuffing / scoring
draft
75.0
High
Supporting evidence present
- Longitudinal score marks (critical)
- smeared/overheated surfaces
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
-
Galling
draft
73.3
High
Supporting evidence present
- Severe torn surfaces (critical)
- seizure marks
- high friction history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
-
Adhesive wear
calibrated
65.0
Moderate
Supporting evidence present
- Surface material loss, scoring, grooves, galling or polishing at contact surfaces (critical)
- Wear debris in lubricant or assembly
- Lubrication deficiency (starvation, degradation, wrong lubricant, dry running)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / wall-thickness survey
- Service-environment chemistry review or sampling
- surface examination
- dimensional survey
- lubricant/debris analysis
-
Fretting wear
draft
mix
60.0
Moderate
Supporting evidence present
- Dark oxide debris (critical)
- polished/rough contact scar
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Loading / stress review
- Macro / visual examination
-
Droplet impingement erosion
draft
41.7
Moderate
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Loading / stress review
- Macro / visual examination
-
Tribocorrosion
draft
mix
41.7
Moderate
Supporting evidence present
- Wear scar with corrosion products (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Slurry erosion
draft
mix
30.0
Low
Supporting evidence present
- Thinning/grooving at flow changes (critical)
- particle impact features
- corrosion products if synergistic
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / thickness survey
- Loading / stress review
- Corrosion-product analysis (EDS/XRD)
-
Two-body abrasive wear
draft
23.3
Low
Supporting evidence present
- cutting/ploughing marks
- wear debris
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
-
Cavitation erosion
draft
12.5
Low
Supporting evidence present
- little corrosion product initially
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Loading / stress review or analysis
- Macro / visual examination
- Loading / stress review
- Corrosion-product analysis (EDS/XRD)
-
Solid-particle erosion
draft
8.7
Low
Supporting evidence present
- impact craters/cutting lips
- thinning at elbows/nozzles
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / wall-thickness survey
- Dimensional / thickness survey
- Loading / stress review
-
Electrical pitting/fluting
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Three-body abrasive wear
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
High-temperature corrosion / hot gas attack
8 in play
-
Nitridation / chlorination
draft
41.7
Moderate
Supporting evidence present
- Nitride/halide products (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Dimensional / wall-thickness survey
- Macro / visual examination
- Dimensional / thickness survey
-
Type II hot corrosion
draft
mix
41.7
Moderate
Supporting evidence present
- Pitting-like hot corrosion (critical)
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Macro / visual examination
- Corrosion-product analysis (EDS/XRD)
-
Metal dusting corrosion
draft
12.5
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Dimensional / wall-thickness survey
- Macro / visual examination
- Dimensional / thickness survey
-
High-temperature sulfidation
draft
10.0
Low
Supporting evidence present
- sulphur-rich corrosion products
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Dimensional / wall-thickness survey
- Macro / visual examination of the fracture and component
- Corrosion-product analysis (EDS/XRD)
- Dimensional / thickness survey
-
Carburisation attack
draft
7.0
Low
Supporting evidence present
- increased hardness
- dimensional/microstructural changes
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- Macro / visual examination of the fracture and component
- Metallography
- Hardness survey
- Macro / visual examination
-
Breakaway oxidation
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Dimensional / wall-thickness survey
- Corrosion-product / deposit analysis (EDS / XRD)
- SEM fractography of the fracture surface
- Dimensional / thickness survey
- Corrosion-product analysis (EDS/XRD)
-
High-temperature oxidation
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Dimensional / wall-thickness survey
- SEM fractography of the fracture surface
- Corrosion-product analysis (EDS/XRD)
- Dimensional / thickness survey
-
Type I hot corrosion
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Corrosion-product analysis (EDS/XRD)
Metallurgical degradation / embrittlement
8 in play
-
Alpha-prime embrittlement
draft
48.0
Moderate
Supporting evidence present
- Hardness/toughness change (critical)
- brittle fracture
- thermal exposure record
Evidence missing
- Hardness/toughness change (Hardness)
Suggested test to raise certainty
- Hardness survey across the section
- Metallographic sectioning and microscopy
- Hardness survey
- Macro / visual examination
- Operating-condition review
-
Strain-age embrittlement
draft
29.2
Low
Supporting evidence present
- brittle fracture tendency
- strain-age thermal history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Operating-condition review
-
Temper embrittlement
draft
20.0
Low
Supporting evidence present
- Intergranular brittle fracture (critical)
- service heat-treatment history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Operating-condition data review
- SEM fractography
- Operating-condition review
- Service-history review
-
Chromium carbide sensitisation
draft
mix
16.7
Low
Supporting evidence present
- intergranular corrosion/SCC
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- Welding record review
- Metallography
- SEM fractography
-
Sigma phase formation
draft
16.0
Low
Supporting evidence present
- Brittle fracture (critical)
- hardness changes
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Metallographic sectioning and microscopy
- Macro / visual examination
- Metallography
- Hardness survey
-
Graphitisation of carbon steel
draft
10.0
Low
Supporting evidence present
- service temperature history
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- Macro / visual examination of the fracture and component
- SEM fractography of the fracture surface
- Metallography
- Macro / visual examination
-
Carbide spheroidisation
draft
8.7
Low
Supporting evidence present
- reduced hardness/strength
- creep deformation association
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- Metallography
- Hardness survey
- Macro / visual examination
-
Irradiation embrittlement / swelling
draft
2.5
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Hardness survey across the section
- Macro / visual examination
- Hardness survey
- Metallography
Manufacturing / fabrication defect states
12 in play
-
Hot tearing
draft
30.0
Low
Supporting evidence present
- Interdendritic crack surfaces (critical)
- oxidised crack surfaces
- location at constrained sections
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination
-
Quench cracking
draft
22.0
Low
Supporting evidence present
- Cracks at sharp corners/section changes (critical)
- high hardness
- no service crack-growth marks
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Macro / visual examination
- Hardness survey
- Service-history review
-
Grinding burn
draft
19.4
Low
Supporting evidence present
- hardness gradient
- surface cracks
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Macro / visual examination of the fracture and component
- Hardness survey across the section
- Loading / stress review or analysis
- Macro / visual examination
- Hardness survey
-
Solidification cracking
draft
18.0
Low
Supporting evidence present
- Centreline/interdendritic weld crack (critical)
- oxidised/segregated surfaces
- no service striations
Evidence missing
- Centreline/interdendritic weld crack (Welding records)
Suggested test to raise certainty
- Welding record review
- Macro / visual examination
- SEM fractography
-
Seam / lamination
draft
17.5
Low
Supporting evidence present
- orientation parallel to rolling direction
- inclusion-lined surfaces
Evidence missing
- Planar internal indication (Non-destructive testing)
Suggested test to raise certainty
- Non-destructive testing (UT / RT / MPI / PT)
- Non-destructive testing
- Macro / visual examination
-
Incomplete penetration
draft
7.5
Low
Supporting evidence present
- fatigue/fracture origin at root
Evidence missing
- Root planar indication (Non-destructive testing)
Suggested test to raise certainty
- Non-destructive testing (UT / RT / MPI / PT)
- Macro / visual examination of the fracture and component
- Non-destructive testing
- Macro / visual examination
- Loading / stress review
-
Lap / fold
draft
3.8
Low
Supporting evidence present
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Corrosion-product / deposit analysis (EDS / XRD)
- Non-destructive testing (UT / RT / MPI / PT)
- Corrosion-product analysis (EDS/XRD)
- Non-destructive testing
- Loading / stress review
-
Hydrogen-assisted cold cracking
draft
mix
2.0
Low
Supporting evidence present
Evidence missing
- HAZ or weld toe/root cracks (Welding records)
Suggested test to raise certainty
- Welding record review
- Service-history record review
- Service-environment chemistry review or sampling
- Hardness survey
- Service-history review
-
Gas porosity
calibrated
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Chemical composition analysis (OES / spectrometry)
- Hardness survey across the section
- fractography at origin
- chemistry vs spec
-
Lack of fusion
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
- Planar weld indication (Non-destructive testing)
Suggested test to raise certainty
- Non-destructive testing (UT / RT / MPI / PT)
- Macro / visual examination of the fracture and component
- Welding record review
- Non-destructive testing
- Macro / visual examination
-
Lamellar tearing
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
- Step-like cracks parallel to rolling plane near welds (Welding records)
Suggested test to raise certainty
- Welding record review
- Macro / visual examination of the fracture and component
- Dimensional / wall-thickness survey
- Macro / visual examination
- Dimensional / thickness survey
-
Shrinkage porosity
draft
0.0
Low
Supporting evidence present
None yet.
Evidence missing
No critical gaps.
Suggested test to raise certainty
- Metallographic sectioning and microscopy
- Macro / visual examination of the fracture and component
- Non-destructive testing (UT / RT / MPI / PT)
- Metallography
- Macro / visual examination
Surface / coating / interface failure
6 in play
-
Plating-induced hydrogen embrittlement
draft
mix
60.0
Moderate
Supporting evidence present
- Delayed brittle fracture after plating (critical)
- intergranular/quasi-cleavage features
- high hardness
- plating history
Evidence missing
- Delayed brittle fracture after plating (Coating / protection records)
Suggested test to raise certainty
- Coating / protection system review
- Coating system review
- SEM fractography
- Hardness survey
-
Coating cracking
draft
mix
45.0
Moderate
Supporting evidence present
- Crack network in coating (critical)
- substrate corrosion at cracks
Evidence missing
- Crack network in coating (Coating / protection records)
Suggested test to raise certainty
- Coating / protection system review
- Operating-condition data review
- Coating system review
- Macro / visual examination
- Operating-condition review
-
Coating delamination
draft
mix
20.0
Low
Supporting evidence present
- interfacial fracture
- corrosion products under coating
- poor surface profile/contamination
Evidence missing
- Lifted coating (Coating / protection records)
Suggested test to raise certainty
- Coating / protection system review
- Coating system review
- Macro / visual examination
- Corrosion-product analysis (EDS/XRD)
-
Scale/coating spallation
draft
mix
12.5
Low
Supporting evidence present
- exposed substrate hot corrosion/oxidation
Evidence missing
No critical gaps.
Suggested test to raise certainty
- SEM fractography of the fracture surface
- Corrosion-product / deposit analysis (EDS / XRD)
- SEM fractography
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Coating blistering
draft
mix
10.0
Low
Supporting evidence present
- fluid/corrosion products beneath
Evidence missing
- Dome-shaped blisters (Coating / protection records)
Suggested test to raise certainty
- Coating / protection system review
- Macro / visual examination of the fracture and component
- Coating system review
- Corrosion-product analysis (EDS/XRD)
- Macro / visual examination
-
Filiform corrosion
draft
mix
0.0
Low
Supporting evidence present
None yet.
Evidence missing
- Filament/thread-like tracks under coating starting at defect or cut edge (Coating / protection records)
Suggested test to raise certainty
- Coating / protection system review
- Coating system review
Landscape: 106 Failure-Mode Cards from MTIS-MET-TAX v0.1 (11 families),
scored by the confidence model. The 8 calibrated cards are expert-tuned; the rest are AI-drafted and weight-calibrated
pending expert review. Material applicability is a draft inference pending the owner's material-classification card.