Upload
trinhnhu
View
241
Download
6
Embed Size (px)
Citation preview
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010
Failure Analysis on a Broken ICE3 Railway Axle
Interdisciplinary
Approach
Federal Institute for
Materials Research and TestingWorking
Group „Failure
Analysis“
with
results
from
divisionsV.3, V.1, V.2, VI.1, VI.3, VIII.3, VIII.4 …
C. Klinger
D. Bettge, R. Häcker, T. Heckel, D. Gohlke, D. Klingbeil …
Bundesanstalt für Materialforschung und -prüfung
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010
Customers
for
WG „Failure
Analysis“
•
Police, State Attorney,
Court of Justice
•
Government Ministry
•
Public authorities
for
railways, motor
vehicules
and ships
•
Industry
•
Insurance
•
Standardisation
bodies
•
The
Media
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010
Cases
of damage
from
different technological
areas
EXAMPLES
•
Mechanical
and Plant Engineering: Boilers…
•
Transportation: Railway,
Ships, Airplanes, Vehicles
•
Transportation
of dangerous
goods: Containers…
•
Gas Safety
Engineering: Valves
•
Medical
Engineering: Implants
•
Structural
Engineering: Overhead
Eletrical
Power Towers
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 4
Interdisciplinary
Failure
Analysis for
complex
accidents
Numerical Analysis
Non Destructive Testing
Materials Testing
Service loading
fatigue
Corrosion
mechanical
engineering Microstructure
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 5
Derailment
of ICE3 at Köln Hbf on 9. July
2008
ICE 518, Hohenzollern Bridge [press photo]
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 6
Derailing
of a Motor Wheelset
Bild ICE3 auf der Hohenzollernbrücke hierher
[press photo]
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 7
ICE3: Failure
of a Motor Axle
Quelle: ARD, Monitor 2008-
11-06
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 8
Task
given
by
state
attorney
Köln, July
2008:
Accident
Analysis of the
derailment
of ICE 518
•
Material-, Production-
or
Maintenance
Defects•
Deficiencies
of the
vehicle
•
Compliance
with
the
rules•
Root
Cause for
failure
Senior Prosecutor
Köln Februray
2010: authorisation
for
„open
discourse
within
scientific
associations“
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 9
Position of broken
wheelset
within
the
train, fracture
surfaces
fracture
surface
FA, axle, gear
box, wheel
AWheel B, fracture
surface
FB
403 510
2. Klasse
403 610
2. Klasse
403 810
2. Klasse
403 710
2. Klasse
direction
of train
Bridgemain
station
Köln
(sketch
DB AG)
(press photo)
within
Bogie
-
trailing
wheelset
heading
for
Köln; -
leading
wheelset
heading
for
Dortmund
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 10
Broken wheelset
with
gearbox
coupling
gearbox axle
bearing
wheel
discside
A
wheel
discside
B
location
of fracture
freefit
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 11
Increased
Loading
on the
axle? Inspection
of components
in the
motor
bogie
Air spring
damper
lever
primary
springReplacement: Trailing
Wheelset
motorsupport
bogie
frame
coupling
brake
damage
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 12
Damage
on the
bogie
frame
(corner
2R): smeared
material caused
by
wheel
contact
rotation direction
of wheel
=> Contact
wheel
–
frame
while
train
heading
to Köln
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 13
Mechanized ultrasonic inspection of axles•
Damaged
axle: areas
with
three-centre
curves
and hutches
•
Comparative
specimen: Area
of fracture
and and
areas
with
three-centre
curves
and hutches
side
A(gear)
side
B
center
inner surface
outersurface
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 14
UT testings
of broken
wheelset
axle
# …419 before
failure
•
UT testing
on volumetric
defects
by
manufacturer: recording
level
set to 1 mm DSR (Disk Shaped
Reflector)
=> no indications
•
UT testing
on horizontal oriented
crack
type
defects
by
manufacturer: recording
level
set
to 2 mm SCD (saw
cut
depth)
=> no crack-type
indications•
UT in-service
inspection
on crack
type
defects
(outer
surface):
recording
level
set
to approx. 2 mm SCD [reported
by
DB] UT testing
with
HPS unit
by
DB AG:
RSW 2660419 on 2008/03/27 => no crack-type
indications
Used
standards
and proceedings
for
UT testing: Richtlinie ZfP-US-Radsatz-Laengsbohr-907.0201-neu
US-Prüfung Tz406-907.9043
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 15
UT testings
of broken
wheelset
axle
# …419 at BAM
•
Manual operated
mechanized
UT testing
on both
parts
of broken wheelset
axle
[recording
level
approx. 1 mm SCD]: => no crack-type
indications!
•
Manual operated
mechanized
UT testing
on axle
from
same
batch [recording
level
approx. 1 mm SCD]: => no crack-type
indications!
•
Manual UT testing
close
to crack
with
focus
on parallel cracks => no crack-type
indications!
•
Manual MT testing
close
to crack: => no crack
type
indications!
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 16
Material investigations (destructive)
•
Separation of the
broken
wheelset•
Mechanical
tests
•
tensile
test•
impact
test
•
Chemical analysis•
Fractography
•
Metallography•
Identification
of purity
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 17
Separation of the
broken wheelset
oxygen
cutting
of the
axle
Cutting
of axle
journal, side
Awheel
disc: force out of the
axle
Side A
side
A
side
B
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 18
Part of the
axleFit Fit of wheel Fit of gear
box Free fit
Sampling
Side A Side B
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 19
Driven
wheelset
axles
ICE3•
Realisation: high strength
steel
allows
for
higher
stresses
•
Disadvantage: crack
growth rates
for
steel
are
unaffected
by
material grade:
•
higher
operation
stresses
will lead
to increased
defect
growth rates:•
10% increase
in stress level
reduces
the
inspection
interval
by
200 …
300% [Benyon2001]
•
[Benyon, J.A. and Watson, A.S. (2001): The use of Monte-Carlo analysis to increase axle inspection interval. Proceedings of the 13th Int. Wheelset
Congress , Rome, Italy]
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 20
Mechanical
tests: sampling
Different standards
for
product
and material:•
E_EN 13261:1998 Wheelsets
, Product
requirements•
EN 10083-1:1996 Steels for quenching and tempering, General technical
delivery conditions
Specimens
forEN 10083-1 EN 13261
Tensile
test quantity: 1Distance to surface
12,5 mm
min. ∅
10 mmquantity: 3between
Ri
und Ra
Impact test ISO-V-specimen
quantity: 3 , axialDistance to surface
12,5 mm
ISO-U-specimenquantity: 9+9 , axial and across,between
Ri
und Ra
Chemical analysis without
requirements
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 21
Tensile
Tests
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 22
Mechanical
tests
ReH
in MPa
Rm
in MPa A in % Z in %
K in J
Required
values
„Techn. Spezifikation /Liefervorschrift für Radsätze ICE 3“
03/97
900…1050
EN 10083-1:1996 for
100mm < d < 160 mmfor
160 mm < d < 250 mm≥
700≥
600900…1100800…950
≥
12≥
13≥
55≥
55KV
≥
45KV
≥
45
Actualvalues
Test results 889 982 17...30 67 KV = 109
KU long. = 56 / 57 / 54trans. = 49 / 50 / 44
„similar
to EN 10083-1“
Strength, ductility, toughness
and impact
energy
are
conform
to the requirements
of EN 10083.
comparison
of requirements
and results
EN 10083-1:1996 Vergütungsstähle, Technische Lieferbedingungen für Edelstähle
outs
ide
mid
dle
insid
e
Auße
n+In
nen
Mitt
e
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 23
Gradient of material properties
across
the
cross section?•
Sampling
and test of ISO-V-specimens
out of the
area
of crack
inititiation•
Axial specimen
Location
of specimen
Mean
valuearea
of crack
inititiation 110 JOpposite
to the
area
of crack
initiation109 J
No gradient
in m. p. detectable
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 24
Fractographic
Examination
•
Allocation
of the
fracture
surfaces
to each
other
•
Fracture
mechanism
(e.g. forced
fracture
or
fatigue
fracture)
•
Allocation
of crack
origin
•
Amounts
of fatigue
fracture
and residual fracture
•
Further
details
in the
fracture
surface
•
=> Description
of cracking
process
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 25
Fractography•
Removing
the
fracture
surfaces
Fracture
surface
FA Fracure
surface
FB
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 26
FA•
Marking
of visible
beachmarks
an other
features
visible
beach
mark
supposed
beach
mark
crack
origin
max
. WS
FA
min
. WS
FA
„twirl“
residual fracture?
•
Crack origin
is
extrapolated
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 27
FB
visible
beach
mark
supposed
beach
mark
min
. WS
FB
max
. WS
FB
„groove“
residual fracture?
•
Marking
of visible
beachmarks
an other
features
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 28
Allocation FA to FB
•
Image of FA with
features
of FA (yellow) and FB (green, mirrored)
„twirl“/“groove“
residual fracture
min.
WS
FB
max
. WS
FB
max
. WS
FA
min
. WS
FA
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 29
Fatigue Crack•
Confirmation
of the
fatigue
fracture: beachmarks
(visual) and fatigue
striations
(SEM)
crack
origin
20 mm
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 30
Residual Fracture on FB
rubbed
fracture
surfaceductile
forced
fractue
„groove“
SEM: forced
fracure
10 mm
50 μm
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 31
Crack Propagation•
Illustration of the
fracture
mechanism•
Estimation
of the
area
fraction
of the
residual fracture
Crack origin
Residual fracture
minimum
maximum
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 32
Crack Propagation
Cracking
sequence:1)
Fatigue
crack,
propagation
on both sides
of the
hole
2)
Small residual fracture3)
Rubbing of the fracture surfaces
schematic
1) 1)
1)1)
1)
2)3)
3)3)
3)
3)
3)
3)
3)
3)
3)3)3)
3)
3)
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 33
Cutting FA
Cutting
Fractography
Crack origin
SEM
SEM
SEM
FA-01FA-02
FA-03
Cutting
Metallography
FA-01-01FA-01-02
FA-01-04FA-01-05
FA-01-03
CT
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 34
“Secondary Pattern”Superposition of 3
features:•
Primary: fatigue
crack•
Secundary: line
pattern•
Tertiary: rubbed fatigue
crack
rubbed
line
patterns
rubb
ed
rubbedfatigue
crack
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 35
Interpretation of Secondary PatternMechanism
(hypothesis)
•
Clearly
defined
torsional
movement
of FB around
the
„twirl/groove“
site
just before
final fracture
of the
axle•
secondary
line
pattern
by
imprinting
the
edge
of FA into
FB•
then
final fracture
•
Estimation
of the
driven
distance during
generation
of the
secondary
line
patterns: Wheel diameter
920 mm, 80 lines
=> 230 m driven
distance•
Final fracture
somewhere
before
Köln main
station
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 36
Results Fractography
•
Final fracture
of the
axle
before
Köln Hbf
•
Fatigue
crack
caused
by
rotational
bending
•
Residual fracture
about
1/5th of fracture
surface
•
Crack origin
Site localised, but
not
evaluable
•
Succesful
allocation
of the
fracture
surfaces
to each
other
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 37
•
Baumann print
of disc
SQ•
Result: similar
to images
in UIC 811-1•
Rating: OK
Investigation of segregation
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 38
•
Disc SQ polished•
Result: coarse
dendrites
near
the
crack
origin•
Rating: questionable
Dendrites
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 39
Hardness•
Polished
disc
SQB•
Methods: HV10 and HRC, 3 line
scans
each
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 40
0
50
100
150
200
250
300
350
0 10 20 30 40 50 60
Entfernung zum Außenrand in mm
Här
te in
HV1
0
Reihe 3 BruchausgangReihe 4Reihe 5
Hardness•
Result: no differences
between
crack
origin
an the
other
sectors•
Rating: OK
0
5
10
15
20
25
30
35
0 10 20 30 40 50 60
Entfernung zum Außenrand in mm
Här
te in
HR
C
Reihe 6, BruchausgangReihe 7Reihe 8
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 41
Microstructure•
Quenched
and tempered
with
Bainite•
Matching
the
target
state
cross section plain
section
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 42
Grain Size•
Target state: CEN draft
TL256/SC2/WG11:1997, grains
smaller
than
class
5 (62 μm)
•
Result: class
6/7 (30 μm) => OK
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 43
Metallographic Investigation
•
Macro Structure – OK•
Hardness
–
OK
•
Microstructure
–
OK•
Grain Size – OK
•
Surface
Roughness
–
OK
•
Purity
Level?
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 44
Micro CT Investigation of Crack Origin
Cube
containing
the
crack
origin (FA-01-02)
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 45
Investigation of Crack Origin•
NDT of volume around crack origin by Micro-
Computertomography
(µCT)
•
strong
secondary
deformations
after
final fracture
FA-01-02
1 cm
FA-01-02
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 46
Cutting Through the Crack Origin •
Cross section
of the
crack
origin•
=> highly
deformed
estimated
original shape
of the
crack
origin
region
-t
a
-r
a
r
CT model
of the
crack
origin
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 47
•
Cross section
through
the
crack
origin•
Recrystallisation
of the
surface
region
due
to overheating
base
structure
recystallisation
a
r
Deformation of the Fracture Surface
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 48
µCT Crack Origin•
Large indications
A1, A2 und A3: Inclusions?
•
Definition of coordinates
for
arget
preparation
A2
A3
A1
Dimensions
of the
indications:A1: 698
x 133
x 33
µmA2: 930
x 133
x 33
µmA3: 399
x 100
x 33
µm1 Voxel
~ 16µm³
(a
x r
x t)-t
a
-r
-t
a
-t
a
CT plane r
5 mm
CT-plane r
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 49
•
Confirmation: A1 is
an inclusion•
Some
more
inclusions
up to 40 µm are
visible-t
a
-r
Length
of inclusion
A1 perpendicular
to this
plane is
~700 μm!
-t
-r
corss
section
outer
surface
Metallographic Preparation of Indication A1
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 50
Examples of Inclusions
100 μm 100 μm
a
r
a
r
length
275 µmwidth
58 µm
length
350 µmwidth
30 µm
for
both
inclusions:length
and width
are
not
acceptable
-t
a
-r
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 51
Nonmetallic Inclusions•
Morphology
similar
type
„C“
according
to ISO 4967:1998 •
Chemical analysis
(EDX): oxides
and sulfides•
Rating: due
to casting
process
5: S, Ca, Al, Mn, O
6: Al, O, (Ca)
1: Al, O, Ca, Si
3: Al, O
10 μm-t
-r
5 μm
a
r
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 52
Nonmetallic Inclusions•
ISO 4967:1998
Type C acceptable up to length of 176 µm•
Rating
of the
big
inclusions
found: not
acceptable
a
r
length
550 µmwidth
30 µmtype
C 2,5e + unacceptable
width
-t
a
-r
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 53
Purity according to ISO 4967:1998 (E) Method A
near
crac
kor
igin
far a
way
Rating: Purity
level
is
not
acceptable
A: Sulfid-Typ B: Alu- Typ C: Silicat-Typ D/DS: Typ globulare Oxide
Einzelwerte, dicke Serie, maximal Summe B+C+D Zulässige Werte nach Entwurf CEN TL 256… Kategorie 1
A ≤ 1 Länge < 261 µm
B ≤ 1 Länge < 184 µm
C ≤ 1 Länge < 176 µm
D/DS ≤ 1 D: Anzahl < 9 DS: Durchmesser < 27 µm
B+C+D ≤ 2
Probe Messergebnisse zulässig/unzulässig
FA-01-02 A 1 Länge >127 µm bis ≤ 261 µm Dicke ≥ 2 µm bis ≤ 4 µm
(keine) C 2,5e Länge ≥510 bis <746 µm Dicke > 5 µm bis ≤ 12 µm
D 0,5e 1 bis 3 Einschlüsse im Messfeld Dicke ≥ 8 µm bis ≤ 13 µm
3
SQ(A)-01-03 A 1 e Länge >127 µm bis ≤ 261 µm Dicke ≥ 4 µm bis ≤12 µm
(keine) C 0,5 Länge >18 µm bis ≤ 76 Dicke ≥ 2 µm bis ≤ 5 µm
DS 2 einzelner Einschluss Ø > 38 bis ≤ 53 µm
2
SQ(A)-02-03 A 1 e Länge >127 µm bis ≤ 261 µm Dicke ≥ 4 µm bis ≤12 µm
(keine) C 0,5 Länge 18 µm bis ≤ 76 Dicke ≥ 2 µm bis ≤ 5 µm
DS 2 einzelner Einschluss Ø > 38 bis ≤ 53 µm
2
SME-01-03 A 1 Länge >127 µm bis ≤261 µm Dicke ≥ 2 µm bis ≤4 µm
(keine) C 0,5 Länge 18 µm bis ≤ 76 Dicke ≥ 2 µm bis ≤ 5 µm
D 0,5 e 1 bis 3 Einschlüsse im Messfeld Dicke ≥ 8 µm bis ≤ 13 µm
0,5
SAE-01-03 A 1 Länge >127 µm bis ≤261 µm Dicke ≥ 2 µm bis ≤4 µm
(keine) C 0,5 e Länge 18 µm bis ≤ 76 Dicke > 5 µm bis ≤12 µm
DS 1,5 einzelner Einschluss Ø > 27 bis ≤ 38 µm
2
TC
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 54
Inclusion at the Axle Surface•
Roughness
OK•
Disc with
fracture
surface
FB•
SEM investigation•
Rating: inclusion, Aluminum
oxide
a
t
EDX measurement:
Al, O
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 55
Using UT imersion
Technique for the detection of inhomogenities
and sizing of non-metal inclusions
Disc SQC
UT imersion
tank BAM-VIII.43
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 56
Accumulation of indications in a specific sector
side
A side
B
Combination
of sectorswith
relevant volumetric indications
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 57
Purity grade: Gap in standards •
Standard „Radsatzwelle für Hochgeschwindigkeitsverkehr“
Non-metal
inclusions
Type C up to
length
of 176 µm
accepted
•
NDT inspection
by
manufacturer: recording
level
1 mm DSR
•
In-service
inspection
by
operator: recording
level
2 mm SCD
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 58
Results: Purity of axle material•
Nonmetallic
Inclusions
of unacceptable
size
detected
•close
to the
surface
and•on the
surface
in the
recess
•close
to the
crack
initiation
area• in a sector
over
the
whole
lenght
of the
axle
•
Requirements
on Puritiy
are
not
fullfilled
•
Nonmetallic
Inclusion
initiated
fatigue
crack?
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 59
Fatigue Crack Initiation at very high cycles•
Failure
1977: crankshaft
for
6 cylinders,
journal
diameter
200 mm, thickness
of crank
arm 58,5
mm•
fatigue
fracture
at 3. crankshaft
journal
after
~ 6 ·
107 cycles
[BAM Test Report 1.2/11323]
Fatigue
crack
start
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 60
Crankshaft
failure•
Material 34CrMo4, inductiv
hardened
•
Initiation ~ 0,5 mm below
the
surface
~1,5mm
beach
marks
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 61
Initiation of fatigue
crack
at nonmetallic
inclusion•
nonmetallic
inclusion
Al, Si, Ca, Mn, 0 : slag
•
bad position
in the
area
of maximum
stress
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 62
Hypothesis: Root
causes
for
axle
fractureConjunction
of following
contributing
factors:
•
nonmetallic
inclusions
of unacceptable
size
from
production
•
Large nonmetallic
inclusions
have
not
been
detected
after:
•
Casting: metallographic
examination
of the
purity
•
Forging: Ultrasonic
Testing
for
inner defects
with
vertical
probe according
to TL
918
275 A (registration
threshold: 1
mm circular
disk
shaped
reflector)
•
Wheelset
assembly: Ultrasonic
Testing
for
transverse
defects•
Very
high cycles
in service
3 ●
106
km ~ 109
cycles
•
highly
utilised
axle
=> Initiation of fatigue
crack
in the
recess
(three-center
curve)•
fast crack
propagation
due
to high stresses
•
Fatigue
crack
was not
detected
early
enough:•
Registration
threshold
for
UT (~ 2 mm saw
cut
depht) was too
high OR
•
Inspection
interval
(until
July
2008: 300.000 km) was too
long
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 63
Immediate Measures: substancial
reduction
of UT-inspection
interval
•
EBA 10.7.2008: UT of all axles
made
of 34CrNiMo6
60.000 km instead
of 300.000 km
•
currently: 30.000 km
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 64
Consequences
17.7.2009
•
Abatement
of the
investigations
by
state
attorney
Köln:•
the
employees
of Deutsche Bahn can
not
be
prosecuted
… The
impurity
of the
material was not
visible
for
them…•
The
manufactures
of the
axle
may
not
be
accused…
•
[Spiegel online, FTD.de, Handelsblatt, WDR.de, AN online, Berliner Zeitung, taz.de, …17.7.2009 …]
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010 Folie 65
Consequences: Exchange of all motor
axles•
… Deutsche Bahn and manufacturers
Siemens and
Bombardier aggree: …
all ICE3 motor
axles
will be changed
…
•
…manufacturers
designing
new
axles, …
testing, … approval
by
EBA
•
…two
to three
years
until
all 70 ICEs will run
on new
axles.•
… increase
of inspection
intervals.
•
costs
due
to the
problem
with
the
axles
~ 350 Million Euro.“
•
[ARD.de
12.10.2009 and Kölnische Rundschau 13.10.2009]
Failure Analysis on Broken Railway Axle ICE3
BAM-V.3, Klinger et. al. ESIS TC24 Railway Structures, 11. Oct. 2010
Thank
You
very
much
for
your
Attention