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Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc Head of the Institute: Prof. Dr.-Ing. H.-J. Christ
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KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

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Page 1: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

KinCorrModeling of Corrosion Phenomena

Ravisankar Naraparaju M.Sc

Head of the Institute: Prof. Dr.-Ing. H.-J. Christ

Page 2: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

What is KinCorr?

• KinCorr - a computer- based program for simulation of high- temperature corrosion phenomena

• Use of numerical diffusion calculation in combination with thermodynamic equilibrium concepts

• The application KinCorr is parallelized along its functions (function-master, function- slave and function- matlab)

Universität SiegenInstitut für Werkstofftechnik

Page 3: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Physical Modelingand

Computer-Based Simulation

Page 4: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Physical Modeling

homogeneous internal attack

Ni-20Cr-2Ti

TiN

intergranular corrosion attack

M 23C6

austenitic steel

Page 5: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Physical Modeling

outer scale and internal attack

Inconel 625 Si

inward-growing scale

Al 2O3

Cr 2O3

SiO2

low-Cr steel

Fe3O4

+ FeCr2O4

Page 6: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

More realistic systems

Description of corrosion kinetics

ComputerThermodynamics Diffusion

Life-cycle of power plant materials

ChemApp and data-bank

Diffusion in differentphases (corrosion product

and substrate) differentiation of diffusion along alloy

grain boundary and volume

moving boundary conditions

Page 7: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Institut für Werkstofftechnik

Modeling

Universität Siegen

MATLAB

ChemApp

InCorr

solid state diffusion

representation

G = Minimum

local thermodynamicequilibrium

Page 8: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut f ür Werkstofftechnik

Mathematical Modeling

∂∂

∂∂=

∂∂

x

cD

xt

c2

2

x

cD

t

c

∂∂∂∂∂∂∂∂====

∂∂∂∂∂∂∂∂( )TfD =

2

2

2

2

y

cD

x

cD

t

cyx ∂∂∂∂

∂∂∂∂++++∂∂∂∂∂∂∂∂====

∂∂∂∂∂∂∂∂

One-Dimensional

Two-Dimentional

t

cc

t

c jiji

∆,, −−−−

≈≈≈≈∂∂∂∂∂∂∂∂ ++++1

2

11

2

2 2

)(,,,

x

ccc

x

c jijiji

∆−−−−++++ ++++−−−−

≈≈≈≈∂∂∂∂∂∂∂∂

jijijiji rccrrcc ,,,, )( 111 21 ++++−−−−++++ ++++−−−−++++====

2)( x

tDr

∆∆====

One-Dimensional Problem – explicit finite-difference method

jjj bAcc ++++====++++1

−−−−

−−−−−−−−

−−−−−−−−

====

rr

r

r

rrr

rrr

rrr

rr

2100000

0000

02100

00210

00021

000021

......

....

...

...

...

...

A

====

0

0

0

.

.

.b

s

j

rc

2

1≤≤≤≤r

Page 9: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut f ür Werkstofftechnik

One-Dimensional problem – implicit finite-difference method

2

2

x

cD

t

c

∂∂∂∂∂∂∂∂====

∂∂∂∂∂∂∂∂ t

cc

t

c jiji

∆,, −−−−

≈≈≈≈∂∂∂∂∂∂∂∂ ++++1

)()( ,,,,,, 111111122

2

222

1++++++++++++++++++++−−−−++++ ++++−−−−++++++++−−−−≈≈≈≈

∂∂∂∂∂∂∂∂

jijijijijiji ccccccxx

c

jjj b)NI(c)NI()NI(c 111 222 −−−−−−−−

++++ ++++++++−−−−++++====

xMN r====

−−−−−−−−

−−−−−−−−−−−−

−−−−−−−−−−−−−−−−

−−−−

====

2100000

1

01000

012100

001210

000121

000012

......

....

...

...

...

...

M x

Page 10: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Two-Dimensional Problem – implicit finite-difference method

2

2

2

2

y

cD

x

cD

t

cyx ∂∂∂∂

∂∂∂∂++++∂∂∂∂∂∂∂∂====

∂∂∂∂∂∂∂∂

(((( ))))2x

tDr x

x∆

∆==== (((( ))))2

y

tDr y

y∆

∆====

(((( )))) (((( )))) (((( ))))(((( )))) (((( )))) )( ,,,,,

,,,,,

jiyix

jiyixx

jiyixyx

jiyix

jiyixy

jiyix

jiyixy

jiyixyx

jiyix

jiyixx

ccrcrrccr

ccrcrrccr

1111

11

11

111

11

12

12

++++−−−−++++−−−−

++++−−−−

++++++++

++++++++−−−−

++++++++

++++⋅⋅⋅⋅−−−−⋅⋅⋅⋅−−−−−−−−⋅⋅⋅⋅−−−−++++⋅⋅⋅⋅−−−−

====++++⋅⋅⋅⋅++++⋅⋅⋅⋅++++++++⋅⋅⋅⋅−−−−++++⋅⋅⋅⋅

(((( ))))

(((( ))))

(((( ))))

(((( )))))],,(),,(),,([

),(

),(

)],,(),,(),,([),(

),(

)],,(),,(),,([),(

),(

)],,(),,(),,([),(

),(),,(),,(

ttyyxcttyxcttyyxcyxy

yxD

tyyxctyxctyyxcyxy

yxD

ttyxxcttyxcttyxxcyxx

yxD

tyxxctyxctyxxcyxx

yxD

t

tyxcttyxc

y

y

x

x

∆∆∆∆∆∆

∆∆∆

∆∆∆∆∆∆

∆∆∆∆

++++++++++++++++−−−−++++−−−−++++

++++++++−−−−−−−−++++

++++++++++++++++−−−−++++−−−−++++

++++++++−−−−−−−−====−−−−++++

22

22

22

22

2

2

2

2

Page 11: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Diffusion

Thermodynamics

Page 12: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Page 13: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut f ür Werkstofftechnik

outerscale (Fe O )3 4

intercrystallineoxidation (Cr O )2 3

innerscale (Fe O , FeCr O )3 4 2 4

p(O )2

p(O )2

p(O )2

FeCr O2 4

Cr O2 3

Fe O3 4

5 µmDGB

Dx

Deff

Dymovinginterface

Computer Simulation of Oxidation Processes

InCorr

Page 14: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität SiegenInstitut für Werkstofftechnik

Page 15: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität SiegenInstitut für Werkstofftechnik

Only Internal diffusion calculation

Page 16: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Inner layer growth

(((( )))) (((( ))))[[[[ ]]]]422432

2

O)FeCr(OlnO)Fe(Oln pptDeff −−−−

====ξ

Page 17: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut f ür Werkstofftechnik

cFeCr2O4=2At.%

Grain boundaries

Duration = 270 hrsT = 550oCd = 30 µmLab air

Page 18: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität SiegenInstitut für Werkstofftechnik

External diffusion calculation

Page 19: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität SiegenInstitut für Werkstofftechnik

Both internal and external diffusion

Page 20: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

• No proper diffusion coefficient data in inner spinels at required temperatures

• Effective diffusion coefficient of oxygen can be taken in inner scales.

• Here in the oxidation process of 12% Cr steel diffusion coefficient of oxygen in Fe3O4 scale is considered and multiplied with some factor

• Dealing with multi scales especially dealing the counter diffusion of oxygen and iron to form both external and internal scales simultaneously is very complicated.

• Typical example simulation of both external and internal scalesformed on sample steel having 1mol of Fe and 0.5 mol of Cr when oxidized at 700°C for 50h is shown here.

Lack of diffusion data in multi layered oxide scales

Page 21: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Recent work and future aspects

• Addition of outward scale growth• Simulating the effect of shotpeening in KinCorr• Effect of Water vapour on oxidation

Universität Siegen Institut für Werkstofftechnik

Page 22: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Conclusions

Universität Siegen Institut f ür Werkstofftechnik

The high performance of the developed software KinCorr is sustained by a solid theoretical background.

oxidation and internal nitridation of steels carburization of steels

It can be calculated: concentration profiles of C, Cr, Fe, etc.mass gain as a function of time

The developed software KinCorris capable to account for:

local thermodynamic equilibrium,solid state diffusion and alloy

microstructure

Page 23: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut für Werkstofftechnik

Moving Interface Condition and Diffusion Matrix

D11 D12 D13 D14 D15

Di,j =

x,i

y,j D21 D22 D23 D24 D25

D31 D32 D33 D34 D35

D41 D42 D43 D44 D45

D51 D52 D53 D54 D55

Di,j =

Dx = Dy if (i,j) is not a gbandcFe > 0

Dgb if (i,j) is a gbandcFe > 0

Doxide if in (i,j) cFe = 0

time = 100 hdimension = 1 mm2

∆x = ∆y = 0.1 µmnx = ny = 10 000∆t = 1 snt = 360 000 Di,j =

this must be checked 360 000 times at every (i,j)

Page 24: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut f ür Werkstofftechnik

Page 25: KinCorr Modeling of Corrosion Phenomena Ravisankar ...€¦ · Universität Siegen Institut für Werkstofftechnik KinCorr Modeling of Corrosion Phenomena Ravisankar Naraparaju M.Sc

Universität Siegen Institut f ür Werkstofftechnik