precipitation of carbo- nitrides in model steels · 2017-02-23 · université de lyon, mateis, umr...

Université de Lyon, MATEIS, umr CNRS 5510, INSA-Lyon, Bât. B. Pascal,

F-69621 Villeurbanne Cedex

Thierry [email protected]

Precipitation of carbo-nitrides in model steels

NbN fcc in ferrite

OUTLINE

Precipitation in the FeNbVC system

Brief presentation of INSA - Lyon

Introduction:context of the work – thermodynamical modelling of the precipitation

Precipitation in the FeNbCN system

The INSA

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CLYM (Centre Lyonnais de Microscopie)

http://clym.insa-lyon.fr

www.metsa.fr

CETHIL, INSA Lyon

IMP, INSA Lyon / Lyon 1and St-Etienne Universities

LaMCoS, INSA Lyon

MATEIS, INSA Lyon

CTµ, Lyon 1 University

IRCELYON, Lyon 1University

LMI, Lyon 1 University

LPCML, Lyon 1 University

LPMCN, Lyon 1 University

INL, Ecole Centrale Lyon /INSA Lyon / Lyon 1 University

LTDS , Ecole Centrale Lyon

LST, ENS-Lyon

LCC, Ecole Nationale des Mines - St-Etienne

CONTEXT of the work spring steels (Mn/Cr alloyed)

High Strength Low Alloyed steels (Nb alloyed)

© Ascometal (www.ascometal.com)

0.024 wt. % of NITROGEN 0.01 wt. %

PRECIPITATION:

Sol. Sol. HARDENING

GRAIN GROWTH control[HYDE et al. SAE

Technical paper,

(1994)]

Inverse Grain Size (1/Ø, nm-1/2)

ASTM Grain Size Number8 9 10 11 12 13 14

1600

1400

1200

1000

Research Investigation

Hyde et al 3 47

Cohen et al 34

8 10 12 14 16 18

SHEARING precipitates

Orowan mechanism

Sol. Sol. HARDENING (interaction dislocations – precipitates)

GRAIN GROWTH control

MECHANICAL RESISTANCE

DECREASES

when GRAIN SIZE

INCREASES

HEAT treatments

ABNORMAL

GRAIN GROWTH

PRECIPITATION

GRAIN PINNING

THERMODYNAMICAL MODELING of the PRECIPITATION

CLASSICAL NUCLEATION THEORY

1) NUCLEATION (driving force: solute supersaturation)

volume energy(spherical shape assumed)

surface energy(g 0.5 mJ/m², no stress effect)

R*R*R*

first nucleigrowing of

first nuclei

+ new nuclei

Pre

cip

ita

tes N

um

be

r

Size

unstable stable (grow)

(dissolve)

R*

DG*

En

erg

y

Radius

[D.A. PORTER, K.E. EASTERLING, Phase transformation in metals and alloys, London: Chapman & Hall, (1992), 514p]

[R. WAGNER, R. KAMPMANN, Materials science and technology: a comprehensive treatment, vol. 5, p. 213-302:

Homogeneous second phase precipitation, John Wiley & Sons Inc., (1991)]

Nucleation rate (N0: number of nucleation sites per unit

volume, t: incubation time, b*: condensation rate of monomers,

Z: Zeldovich's factor)

critical radius R*

nucleation enthalpy

barrier DG*

surface term

volume term


2) GROWTH (driving force: diffusion)

from Fick's law(spherical coordinates)

diffusion coefficient

concentration near the

precipitate/matrix interface

Cprecipitate

R* = Rmean

same (distribution density)

Pre

cip

ita

tes N

um

be

r

Size

Radius

C0(matrix)

Cinterface

so

lute

co

nce

ntr

ati

on

growth rate

R* = Rmean

Further refinements:

- Gibbs-Thomson effect

- non stoechiometric binary

alloyed precipitates

CLASSICAL NUCLEATION THEORY

3) OSTWALD coarsening (consequence of the Gibbs-Thomson effect)

[I.M. LIFCHITZ, V.V. SLYOSOV, J. Phys. Chem. Solids, 19, 1/2,

(1961), 35-50]

[C. WAGNER, Z. Electrochem, 65, (1961), 581] (LSW theory)


CLASSICAL NUCLEATION THEORY (summary)

Evolution of the mean radius Rmean of precipitates

Precipitated volume fraction Vp

Density of precipitates dpRemaining concentration of the solid solution (matrix)

time (log scale)

1) NUCLEATION

2) GROWTH

2bis) shrinkage of smallest precipitates

3) Ostwald coarsening

1)

2)2bis)

3)

t1/3


NUMERICAL CALCULATIONS (multi-class approach)

N

R

ΔNo

Ro*

0*

* exp 1 expdN G t

N Zdt kT

bt

D

* δt

' '

' '

i

p i

C CdR D

dt R C C

N

R

Ro*

R

dR

dt

growth

1) t = tON

R

ΔN1

R1*

2) t = tO 3) t = t1

N

R

4) t = t1 N

R

5) t = tn

R*Rmin

N

R*Rmin

6) t = tn

N

R*Rmin

nucleation

coarsening

[D. ACEVEDO, PhD thesis, (2007), INSA-Lyon]

[D. ACEVEDO, M. PEREZ, Computat. Materials, (2009)]


Precipitation in the FeNbCN system

[M. PEREZ, E. COURTOIS, D. ACEVEDO, T.

EPICIER, P. MAUGIS, Phil. Mag. Letters, 87,

(2007), 645-656 ]

Reversion in the FeVC and FeVNbC systems

[D. ACEVEDO, PhD thesis, (2007), INSA-Lyon]

[D. ACEVEDO, M. PEREZ, T. EPICIER, E.

KOZESCHNICK, F. PERRARD, T. SOURMAIL,

p.987-999 in "New developments on Metallurgy and

Applications of High Strength Steels", Vols 1/2, Min.,

Metals & Mater. Soc., Warrendale – USA,

(2009)]

Reversion and grain growthcontrol in the FeCVNbN system

[C. LEGUEN, PhD thesis, (2010), INSA-Lyon]

Dissolution in the FeVC system

model alloy

Fe - V 0.2 wt. %, C 0.48 %

[D. ACEVEDO, PhD thesis, INSA-Lyon, (2005)]

STUDY of the DISSOLUTIONof Vanadium Carbides during REVERSION treatments

EXPERIMENTAL techniques

Electrolytic dissolution + ICP (Inductive Coupled Plasma) spectroscopy

- Fraction of precipitated elements

- Precipitates statistics

Extraction replicas(+ thin foils) 500 nm

STEM

in

SEM

HAADF in TEM

[ACEVEDO-REYES D.,

PEREZ M., VERDU C.,

BOGNER A., EPICIER T.,

J. of Microscopy, 232, 1,

(2008), 112–122]

Fully Precipitated state (ferrito-perlitic)

20 mm50 mm50 mm50 mm50 mm50 mm 0.2 mm

111VC

martensite

[T. EPICIER et al., Phil. Mag., 88, 1, (2008), 31-45]

ordered V6C5

Reversion states (martensitic)

5 mm5 mm500 nm

FPS state

920°C 60'

920°C 10 days

Rk.1: normalizing histograms

FPS state

Radius (nm) Radius (nm)

Radius (nm) Radius (nm)

Raw measurements Optimized classes

Distribution density Log-normal law

Rk.2: SEM-TEM correspondence

FPS state 920°C 60' 920°C 10 days870°C 2'

TEMSEM

TEMSEM

TEMSEM

TEMSEM

t (min) 870°C 920°C 950°C

0 1227 1227 1227

2 920 394

5 114 606

10 308 356

20 302 533

60 1074 426 345

Radius (nm) Radius (nm) Radius (nm) Radius (nm)

Size of precipitates

Evolution du rayon

moyen lors d'un

traitement à 870°C

1.E-08

1.E-07

1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05

Temps (s)

R (

m)

Model

Exp MEB

Evolution du rayon

moyen lors d'un


1.E-08

1.E-07

1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05

Temps (s)

R (

m)

Model

Exp MEB

Evolution du rayon

moyen lors d'un


1.E-08

1.E-07

1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05

Temps (s)

R (

m)

Model

Exp MEB

870°C

Time (s) Time (s) Time (s)

Rad

ius

(n

m)

Ra

diu

s (

nm

)

Ra

diu

s (

nm

)

Model

exp. SEMModel

exp. SEM

Model

exp. SEM

920°C 950°C

Volume fractionof precipitates

ThermoCalc© values

0

1E+27

2E+27

0.E+00 2.E-08 4.E-08 6.E-08 8.E-08 1.E-07

R (m)

Consistency of results: effect of the 'starting' precipitate distribution

870°C

1.E-08

1.E-07

1.E-03 1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

870°C exp

920°C exp

950°C exp

Ra

diu

s (

nm

)

Time (s)

7

870°C

920°C

950°C

from experimental

distribution

Experimentally observed FP state (SEM / HAADF)

Radius (nm)

1.E-08

1.E-07

1.E-03 1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

870°C simulée

920°C simulée

950°C simulée

Ra

diu

s (

nm

)

Time (s)

7

870°C

870°C

920°C

950°C

from simulated distribution

0

1E+27

2E+27

3E+27

4E+27

0.E+00 1.E-08 2.E-08 3.E-08 4.E-08

R (m)

LSW-type simulatedFull Precipitated state

(after 10 days at 800°C)

Radius (nm)

same

mean

radius

Precipitation in the FeNbCN systemmodel steel

Fe - Nb 790 wt. ppm, C 120 ppm, N 10 ppm(800°C, 30’)

50 nm

HETEROGENEOUS

Precipitation

HOMOGENEOUSprecipitation

heterogeneous precipitation

of NbC (c.f.c.)

in -Fe‘BAKER-NUTTING’ O.R.

[T. EPICIER, Adv. Eng. Mater. 8, 12, (2007), 1197-1201]

50 nm

Model steel

Fe - Nb 843 ppm, C 59 ppm, N 64 ppm(650°C, 30’)

heterogeneous precipitation of NbC (c.f.c.)

and homogeneous precipitation of NbN (c.f.c.)

in -Fe(‘BAKER-NUTTING’ O.R.)

[É. COURTOIS, T. EPICIER, C. SCOTT, Micron, 37 (2006), 492-502]

DF BF DF

2 nm

BAKER-NUTTING O.R.:

[110]F.C.C. // [001]Fe-

[001]fcc // [001]Fe

[110]fcc

// [100]Fe

model steel

Fe - Nb 790 wt. ppm, C 120 ppm, N 10 ppm(800°C, 30’)

Model steel


[001]fcc // [001]Fe

[110]fcc

// [100]Fe

(d220NbC - d100

Fe)

d100Fe

NbC, fcc, aNbC = 4.47 Å

d'in plane' = = 10.28 %

(d220NbC - d100

Fe)

d100Fe

NbN-d, fcc, aNbN = 4.394 Å

d'in plane' = = 8.41 %

-Fe (ferrite):cc, a = 2.866 Å

Perfect fcc structurefor B.N.:

afcc = aFe 2 4.053 Å

(d220VC - d100

Fe)

d100Fe

VC, fcc, aVC = 4.17 Å

d'in plane' = = 2.88 %

2 nm

111

111

-

-

[T. EPICIER et al., Phil.

Mag., 88, 1, (2008), 31-45]

2 nm

-Fe [001]

(110) at 0.203 nm

COMPATIBLE with a Nb-(100) plane in FERRITE

Fe ferrite

Nb

N

Model steel


NOT OBSERVED in the C-rich steel:

NbN platelets?

2 nm

ATOMIC PLATELETS or ‘G.P. zones’ NANO-PRECIPITATES

C

Fe

O

NbNATOMIC

PLATELETS:

N-enriched (?)

EDX nano-analysis

probe 1 nm

0 0.5 1 1.5 2 2.5 (keV)

counts

EVIDENCE for a DOUBLE

POPULATION of ‘OBJECTS’

2 nm

Atom Probe Tomography

CONFIRMATION of a DOUBLE

POPULATION of ‘OBJECTS’

4 nm

Fe

N-enriched

(ATOMICPLATELETS…)

Nb 55 ± 3 at. %

C 8 ± 1 at. %

N 37 ± 2 at. %

0

0.25

0.5

0 5 10 15 20 25 30

0

0.25

0.5

0 5 10 15 20 25 30

0

0.25

0.5

0 5 10 15 20 25 30

0

0.25

0.5

0 5 10 15 20 25 30

NbN

Nb

N

C

analysed depth (nm)

atomic concentration (%)

1 nm

‘carbo-nitrides’

(NANO-PRECIPITATES…)

Nb 47 ± 3 at. %

C 20 ± 1 at. %

N 33 ± 2 at. %

[T. EPICIER, F. DANOIX,

F. VURPILLOT, PTM 2010, Avignon-F,

and to be published]

211

121

121

211

130

310

110

_

_

and Field Ion Microscopy...

CONFIRMATION of both

ATOMIC PLATELETS and NANO-PRECIPITATES

by FIELD ION MICROSCOPY

001 101

011_

_

011

101


211

121

121

211

130

310

110

_

_

Details of the analysis of ATOMIC PLATELETS

FIM evaporation sequence


211

121

121

211

130

310

110

_

_

AA

B B

tr001

tip section (001)

[110]

tr100

tr010


3D analysis of the FIM evaporation sequence

tr001

tr001

tip section (001)

[110]

tr100

tr010



tip projection [001]

[110]

(110)Fe at 0.2 nm

tip section (001)

[110]

tr100

tr010



[110]

tip section (001)

[110]

tr100

tr010tip projection [001]

Back to High Resolution TEM...

indicative HRTEM simulations

df = - 90 nm - 60 nm + 45 nm

experiment / simulation experimt / simulatn experimt / simulatn

AVERAGE PROFILE

ACROSS

the DEFECT

experiment

simulation

‘rough model’:

substitution of

Fe atoms by

Nb atoms in a

(001) plane(NO metalloïd,

NO atomic

relaxation)

total thickness:20 nm Fe +

20 nm platelet (Fe,Nb)

COMPATIBLE with a Nb-(100) plane in FERRITE

Guinier-Preston type ZONES in a pure Fe-Nb-N system

SANS study[DESCHAMPS A., DANOIX F., EPICIER T., DE GEUSER, F., PEREZ M. PTM-Avignon, F, ( 2010)]

I.L.L.,Grenoble-F

Magnetic signal

Nuclear signal

Project O6|BLAN|0205


180

200

220

240

260

Mic

rohard

ness

Microhardness

0

0.01

0.02

0.03

0.04

0.05

1

10

100

10 100 1000 104

105

Volu

me fra

ction (

%)

Pre

cip

itate

density

(10

20 m

-3)

Number density

Volume fraction

Time (s)

10-5

0.0001

0.001

0.01

0.04 0.07 0.1 0.4

Experiment

Model

Magnetic scattering intensity (cm-1

)

q (�-1

)

300 s

10-5

0.0001

0.001

0.01

0.04 0.07 0.1 0.4

ExperimentModel


)

q (�-1

)

600 s

10-5

0.0001

0.001

0.01

0.04 0.07 0.1 0.4

ExperimentModel


)

q (�-1

)

180000 s

10-5

0.0001

0.001

0.01

0.04 0.07 0.1 0.4

ExperimentModel


)

q (�-1

)

1800 s

10-5

0.0001

0.001

0.01

0.04 0.07 0.1 0.4

ExperimentModel


)

q (�-1

)

18000 s

0.01

0.1

0.02 0.06 0.1 0.5

300 s

600 s

1800 s

18000 s

180000 s

Nuclear scattering intensity (cm-1

)

q (�-1

)

0

10

20

30

40

50

60

Asquenched

100 1000 104

105

Rg

Radius

Thickness

Precipitate size (�)

Time (s)

(nm)

TEM[001]-ferrite grain

60 x 60 x 300 nm3 NbN

diameter close to 10 nm

APT


10 nm

50 hrs @ 600°C

80 x 80 x 70 nm3

back to FeNbCN system…

200 nm

HAADF (replica)

substoichiometric CARBO-NITRIDES

average chemistry NbC0.58N0.27

pure NITRIDES Nb1N1

NbC0.57N0.29

NbN1

Nb- M

C-K

N-K

30’ – 650°C 126 h. – 650°C

2 nm

5’ – 600°C

nitride (N) precursor

carbo-nitride (CN)

200 nm

CN

N

N

N

N

CN

Replica (30’ – 650°C)

EELS

Introduction to EELS

V-L2,3513 eV

N-K401 eV

C-K284 eV

x 100

plasmons

elastic zero-loss

peak

core-lossexcitations

1background subtractionpower-law E-r

2Fourier deconvolution(simple scattering)

Sexp(E) = Ssimple(E) Splasmon(E)

Ssimple(E) = TF-1 [ ]TF[Sexp(E)]

TF[Splasmon(E)

]

[R.F. EGERTON, ‘Electron

Energy-Loss Spectroscopy in the

Electron Microscope’, 2nd Ed.,

Plenum Press (1996), 485 p.]

3quantitative analysis

AC

NX AX sY(DE, beff)

NY AY sX(DE, beff)

AN

AV

cross-section for inelastic scattering

DE

collection angle

=

quantitative element analysis

Electron Energy-Loss Near-Edge fine Structures (ELNES)

[A.J. SCOTT et al., Phys. Rev. B, 63, 245105, (2001)]

C-K in ZrC

C-K in NbC

C-K in TiC

C-K in VC

occupied state

3s/3p anti-bond.

3s/3p bonding st.

2p

2s

1s

energy E

fundamental state

D.O

.S. D

en

sity

of S

tate

s

1s excited state

primary electron

DE energy loss

unoccupied states

NbC1

Nb2C

[T. EPICIER, E. COURTOIS, C. SCOTT, unpublished]

EELS in thin foils

FeCrN system[P. JESSNER, PhD, GPM-Rouen]

Fe-L2,3708 eV

Cr-L2,3575 eV

N-K401 eV

O-K532 eV

inadequate background- too thick

- slight C contamination

- cannot extract edge areas

properly

C-K residu

O-KN-K

Cr-L2,3

Fe-L2,3

C-K284 eV

EELS references

Nb-M from NbC0.95, Nb6C5, NbN (powders / bulk single- or poly-crystals)

C-K in NbC from NbC0.95, Nb6C5 (powders / single-crystal)

C-K in VC from V6C5 (bulk poly-crystals)

C-K in amorphous carbon from C-film (TEM grid)

N-K in NbN from NbN (powder)

N-K in TiN VN from TiN (precipitates) and VN (literature)

Ti-L from TiN (precipitates)

Cr-L from CrN, Cr2N

N-K in CrN from CrN

O-K in Fe2O3 from oxidized Fe thin films

Fe-L in Fe2O3 from oxidized Fe thin films

N-Kedge

Cr-L2,3 edge

tail extrapolation

[C. MITTERBAUER et al., Sol. State

Comm.,130, (2004), 209–213]

CrN

Quantitative Least-Mean Square Fitting

from normalized references

Fe-L2,3708 eV

Cr-L2,3575 eV

N-K401 eV

O-K532 eV

Quantitative Least-Mean Square

Fitting from normalized references

Cr1N1

spurious oxidation

CrxFe?Ny platelet

probe 3 nm

Quantitative composition results for the CARBO-NITRIDE precipitates

30 min-650°C 126h-650°C

Nb1C0.59N0.23 = 0.82[C+N]

[Nb]

[C]/[Nb][N]/[Nb]

[C]/[Nb][N]/[Nb]

Nb1C0.58N0.27 = 0.85[C+N]

[Nb]

precipitate = Nb(C1N2

) + bV(Cb1Nb2

) + gTi(Cg1Ng2

) + eCam

+ b + g= 1 0.5 1 + 2 1

0.5 b1 + b2 1

0.5 g1 + g2 1

y [0.5, 1] in

cubic MXy carbonitridese = 0 if NO CONTAMINATION

0

2000

4000

6000

8000

200 250 300 350 400 450 500 550

Energy Loss (eV)

Counts

(a.u.)

ref. 1Nb-M45

ref. 2 C-K*

ref. 3 N-K*

ref. 4Ti-L23 ref. 5

V-L23

reconstructed spectrum

experimental spectrum O-K

(oxidation)

0

2000

4000

6000

8000

200 250 300 350 400 450 500 550

Energy Loss (eV)

Counts

(a.u.)experimental spectrum

(Nb,V,Ti)(C,N) precipitate

Fitting windows

Application to complex mixed carbo-nitrides

[LEGUEN C, PhD thesis, INSA-Lyon, ( 2010)]

MODELLING of NbN + NbCNpopulations

[M. PEREZ, É. COURTOIS, D. ACEVEDO, T. ÉPICIER,

P. MAUGIS, Phil. Mag. Letters 87, 9, 645, (2007)]

G.P. zones:nitride (N)precursors

f.c.c. carbo-nitrides (CN)

Nb

N

C

carbo-nitrides (CN)

nitrides (N)

0

0.1

0.2

0.3

0.4

0.5

0.6

1 10 100 1000 10000 100000 1000000

Time (s)

Xp

Xp_Nb_NbCN

Xp_N_NbCN

Xp_C_NbCN

Xp_Nb (EELS)

Xp_N (EELS)

Xp_C (EELS)

Xp_Nb (TAP)

Xp_N (TAP)

Xp_C (TAP)

Volume fractionAtomic compositions

Precipitation in the FeNbVC system

[D. ACEVEDO, PhD thesis, INSA Lyon, (2007)]

[D. ACEVEDO, M. PEREZ, T. EPICIER et al., Min., Metals & Mater. Soc., (2009)]

A SUMMARY…

- TEM analysis (EDX, HAADF) demonstrates that the dissolution of precipitates

involves the co-existence of TWO populations: V-rich and Nb-rich carbides

STEM-HAADF (6 days @ 950°)%V %Nb (normalized)

99.7 0.3

%V %Nb

8.0 92.0

0.2 mm

- Thermodynamical modelling confirms this process

- Experimental conditions

fatom(q) = Z (Rutherford scattering)

(q = , a0 = e0h2/pm0e

2 - Bohr’s radius -, Z : atomic number)

f²atom(q) Z² and IHAADF(q) roughly Z2

1

2p2a0q2

2sin(q)

l

STEM High Angle Annular Dark Field for CHEMISTRY

Annular detector collection of

INCOHERENT electron scattered

at high angle

NO DYNAMICAL SCATTERING

- Background on HAADF

power-law

IHAADF Z1.89

collection angles

70 – 186 mRad

Quantitative chemistry in ‘mixed’ (V1-xNbx)C precipitates

extraction C-replica of (V,Nb)Cprecipitates within ferrite

%V %Nb (at. normalized)

75.1 24.9

100 0

97.7 2.3

1

1

2

2EDX

analysis

IHAADF Z ( = 1.7 – 2)

the HAADF intensity is‘linearly linked to the chemical

composition for a given thickness

IHAADF

% at. [Nb] in V1-xNbxC

VC (x=0) NbC (x=1)

mass-thickness

IHAADF

[EPICIER T., TOURNUS F., SATO K., KONNO T., IMC17, (2010)]

dedicated software

to analyse the

HAADF images

(quantitative

measurement of the

intensity assuming

spherical particles)

normalization to a given thickness

(e.g. 50 nm)

size (nm)

size (nm)

normalization to a given thickness

(e.g. 50 nm)

size (nm)

size (nm)

"pure VC"

"pure NbC"

IHAADF = (1-x)IV + xINb + ICin V1-xNbxC

Intensity normalized at 50 nm vs. "chemistry"

accuracy on the [Nb] at.

content 20 %

(non-spherical particles) Intensity

Illustration (alloy Fe-(V,Nb)C: reversion at 950°C)

mean [Nb] (at.%)

normalized histogram of chemical composition

570 particles

normalized histogram of chemical composition

235 particles

mean [Nb] (at.%)

950°C, 0’ (reference state) 950°C, 120’

570 particles in HAADF

97 particles in EDX

0.1 mm

1

2

3

4

5

6

7

9 10

11

12

8

detail

EDX

[V] at. % [Nb] at. %

1 8.9 91.1

2 8.0 92.0

3 3.3 96.7

4 5.1 94.9

5 5.7 94.3

6 6.9 93.1

[V] at. % [Nb] at. %

7 98.6 1.4

8 95.6 4.4

9 99.8 0.2

10 98.0 2.0

11 100.0 0.0

12 97.4 2.6

LARGE V-rich particles, SMALL Nb-rich particles

Thermodynamical modelling

0.0%

0.1%

0.2%

0.3%

1.E-03 1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

Temps (s)

Fra

cti

on

Vo

lum

iqu

e

VC ModèleNbC ModèleVC DosageNbC Dosage

Vo

lum

e f

rac

tio

n

Time (s)

0

20

40

60

80

100

1.E-03 1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

Temps (s)

% a

t d

e V

an

ad

ium

Model

Dissolution + dosing

HAADF

0

20

40

60

80

100

1.E-03 1.E-01 1.E+01 1.E+03 1.E+05 1.E+07

Temps (s)

% a

t d

e V

an

ad

ium

Model

Dissolution + dosing

HAADF

Va

nd

ium

at.

%

electrolytic dissolution

TEM-HAADF Time (s)

global enrichment in [Nb] as a function

of time:

coarsening / dissolution of VC-rich

precipitates

Nio

biu

m a

t. %

Time (s)

Acnowledgements

Frédéric DANOIX, GPM-Rouen (AP)FIM

Frédéric De GUEUSER, Williams LEFEBVRE, GPM Rouen alliages Al-(Mg,Si)

Églantine COURTOIS, Michel PEREZ, Claire LEGUEN, MATEIS Lyon système FeNbCN

Rachid EL BOUAYADI, Daniel ARAUJO, MATEIS Lyon HAADF quantitatif

Gilbert THOLLET, Annie MALCHÈRE, Agnès BOGNER, Daniel ACEVEDO, MATEIS Lyon MEB/ESEM

J. DOUIN, CEMES Toulouse, Patricia DONNADIEU, SIMAP Grenoble images GPA

Centre Lyonnais de Microscopie

Pascale BAYLE-GUILLEMAUD, CEA Grenoble, Béatrice VACHER, ECL Écully EFTEM

precipitation of carbo- nitrides in model steels · 2017-02-23 · université de lyon, mateis, umr...

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