Stress-peening - OSK Kiefer GmbH

Stress-peening
Verfestigungsstrahlen
Stress-peening
O
K
S
O
K
O S K unter Vorspannung
Yield
point of material
Materialfließgrenze
Yield
Yield point
point of
of material
material
Compressive
stress
Druckspannung
Compressive
Compressive stress
stress
0
0
0
Tensile
stress
Zugspannung
Tensile
Tensile stress
stress
stress by applied bending load
= Vorspannung
=
by
applied
bending
load
= stress
stress
by stress
appliedafter
bending
load
resultant
shot peening
in induzierter
the stressed condition
= Resultierende
aus Vorspannung
und
=
resultant
peening
in
durch
Verfestigungsstrahlen
= Druckeigenspannung
resultant stress
stress after
after shot
shot
peening
in the
the stressed
stressed condition
condition
= resultant stress after stress-peening in the relieved condition
=
resultant
the
= Eigenspannung
resultant stress
stress after
after
stress-peening
in
the relieved
relieved condition
condition
nach stress-peening
Entlastung der in
Vorspannung
Shot peening induces compressive residual stress in a surface layer. The distributiUnabhängig
vom
Spannungszustand
eines
Bauteiles
stellt sich
nach
VerShot
peening
compressive
residual
stress
in
The
distributiShot
peening
induces
compressive
residual
stress
in a
a surface
surface
layer.
The dem
distribution and
level ofinduces
this residual
compressive
stress
depends
only onlayer.
the material,
depth
festigungsstrahlen
eine
Druckeigenspannung
in
Abhängigkeit
von
Werkstoff
on
level
residual
stress
depends
on
and
level of
of
this
residual compressive
compressive
stress layer.
depends only
only on
on the
the material,
material, depth
depth
andand
intensity
of this
the plastically
deformed surface
und
Plastifizierung
ein.
and
intensity
of
the
plastically
deformed
surface
layer.
and
intensity
of the
plastically
deformed
surface or
layer.
Already
existing
stress,
produced
by machining
external load, has no influence on
Werden
Bauteilestress,
betriebsund konstruktionsbedingt
nur schwellend,
d. influence
h. nur in eiAlready
produced
by
load,
on
Already
existing
stress,
produced
by machining
machining or
or external
external
load, has
has no
no
influence
on
this fact.existing
ner
Richtung
auf
Zug
beansprucht
(z.
B.
Kipphebel,
Federn,
Zuganker,
Dehnschrauthis
fact.
this
fact.peening can be applied if parts are only loaded in one direction.
Stress
ben),
diese
Vorspannung
die Bauteile
Stress
peening
can
be
if
are
loaded
in
direction.
Stresskönnen
peening
canunter
be applied
applied
if parts
partsgestrahlt
are only
onlywerden.
loadedDabei
in one
onewerden
direction.
in geeigneten Vorrichtungen mit Betriebsspannungen elastisch bis ca. 50 % der
Fließgrenzspannung
belastet
und adie Zugspannungsseite in diesem Zustand VerIn the stress peening
process,
In
the
stress
peening
process,
a
festigungsgestrahlt.
In
the
stress
peening
process,
a
part is shot peened in a externalpart
is
shot
peened
in
a
externalpart
is shotorpeened
in acondition
externally loaded
stressed
Nach
der Strahlbehandlung
werden die
ly
loaded
or
stressed
condition
ly
loaded
or
stressed
condition
by
using
a
fixture
or
weight
toentlassiBauteile
von
der Vorspannung
by
using
a
or
to
by
using the
a fixture
fixture
or weight
weighttensile
to sisimulate
operating
tet.
Dabeithe
addieren
sich die tensile
Druckvormulate
operating
mulate
the
operating
tensile
stress.
spannungen
aus dem Verfestigungsstress.
stress.
After shotmit
peening
the parts will be
strahlen
den Umkehrspannungen
After
shot
the
be
After
shotofpeening
peening
the parts
parts
will
be
relieved
the
applied
load, will
which
aus
der
elastischen
Vorspannung
und
relieved
of
the
applied
load,
which
relieved
ofanthe
applied
load,
which
produces
even
higher
compresführen
zu
extrem
hohen
Druckeigenproduces
an
even
compresproduces
an stress
even higher
higher
compressive residual
upzur
to the
yield
spannungen
bis
hin
Fließbzw.
sive
residual
stress
up
to
the
yield
sive
residual
stress
up
to
the
yield
stress of the material.
Streckgrenze.
Die
Betriebsfestigkeit
stress
of
material.
stress
of the
thestrength
material.and endurance
The fatigue
dieser
Bauteile
reagiert
entsprechend.
The
fatigue
strength
and
The
fatigue
strength
and endurance
endurance
limit are modified accordingly.
limit
are
modified
accordingly.
limit are modified accordingly.
Rocker arm in a
Ventilkipphebel
einer
arm
a
Rocker
arm in
inin
a fixture
toggle Rocker
lever prestress
Kniehebelvorspannvorrichtung
toggle
toggle lever
lever prestress
prestress fixture
fixture
62
63
63
Stress-peening
O SOKS KStress-peening
LeafLeaf
spring,
spring,
decarburized
decarburized
[ % Rm
[%
] Rm ]
+ 40 + 40
0
0
- 20
- 20
- 40
- 40
- 60
- 60
- 80
- 80
Residual stress
Residual stress
+ 20 + 20
[%]
[%]
240
240
220
220
200
200
180
180
160
160
140
140
120
120
100
100
Bending stress
Bending stress
0
80
10
0 0.1
0.1 0.2
0.2 0.3
0.3 0.4
0.4 0.5
0.5 0.6
0.6[mm] [mm]
Distance
Distance
from from
surface
surface
80
4
104
105
105
106
106
107
107
108
108
Cycles
Cycles
= not shot
= notpeened
shot peened
= shot=peened
shot peened
(normal)
(normal)
= stress-peened
= stress-peened
( externally
( externally
loadedloaded
with about
with about
50% of50%
Rmof
) Rm )
64 64
63