hot dip aluminizing process for tbm applications - an overview
DESCRIPTION
Hot Dip Aluminizing Process for TBM applications - An Overview. Nirav I. Jamnapara , S. Mukherjee, P. M. Raole, E. Rajendrakumar INSTITUTE FOR PLASMA RESEARCH Gandhinagar – 382044, India. About LLCB. Solid + Liquid Breeder Concept - PowerPoint PPT PresentationTRANSCRIPT
Venue: IPR, Bhat, G’nagar, India22-July-2008
Workshop on Steels & Fabrication Technologies 200821-22 July, 2008
Organized by: IPR & IGCAR
Hot Dip Aluminizing Process for TBM
applications- An Overview
Nirav I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarINSTITUTE FOR PLASMA RESEARCH
Gandhinagar – 382044, India
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
About LLCB
Solid + Liquid Breeder Concept
Li2TiO3 pebbles as solid breeder & Pb-17Li Eutectic as liquid breeder.
Fig 1: Open view of LLCB TBM
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Schematic 450-900 C
2
325 C PbLi in
460 C PbLi out
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Environment & Challenges
Liquid Pb-17Li @ 1.2 MPa, 325-460 C, 0.5-1 m/s velocities [1] – Hot Corrosion-erosion
T generation in CB & Pb-Li circuits [1] – Tritium permeation through FMS
Thermal Cycles [1]
MHD effects [1] – Insulation needed
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Why coating?
Fig 3: T permeation into coolant from Pb-17Li blanket by Reiter [2] Fig 4: Permeability of several metals by P.S. Korinko [3]
Crsn
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Ideal Coating Should…
Protect FMS against corrosion from Pb-17Li (> 10,000 hrs) [5, 6]
Resist Tritium permeation through FMS (PRF > 75 in Pb-17Li conditions) [4]
Maintain thermal compatibility ()
be Electrically insulating (to resist MHD effects)
not affect heat transfer be easy to apply on substrates
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Candidate coatings
Type of coatings Thickness Agency / Country Year reported
Fe-Al+Al2O3150-180 m FZK Germany (HDA),
& CEA France (CVD)Feb-Sep ’04
Al2O3100 m JRC, Ispra, Italy (VPS) Feb 2004
Er2O3 1 m IPP, Germany (PVD) Aug 2007
Cr2O3-SiO2)+
CrPO4
80-200 m JAERI, Japan (CDC) Nov 2001
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Why Aluminide coating?
Good resistance to T permeation* Good corrosion resistance of FMS against
liquid Pb-Li (480 – 550 C) Thermally compatible Electrically Insulating top layer (Al2O3)
Volume resistivity: 0.01 m
*EU Fusion Technology Program has considered aluminide coatings as ‘reference coating’ (HDA & CVD) as tritium permeation barriers.
Ref # 09: J. Konys et. al., FZK Germany
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Comparison
Coating\Properties Max. thickness reported
Corrosion Resistance
Thermal shock resist.
TPR (PRF)
Al2O3 100 m Very good poor 100-1000
Fe-Al+Al2O3 180 m Good Very good 1000
Er2O3 1 m Not reported Not reported 800
(Cr2O3-SiO2)+CrPO4 80-200 m Not reported good 1000
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Why Hot Dip Aluminizing?
Aluminizing possible by solid, liquid & gas processing [3]
Better PRFs with H2 as compared to CVD (J. Konys; FZK, Germany, [4])
Ease of processing complex geometries Scalable Adherent alumina by oxidation of surface
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Targeted Aluminide Coating
Intermetallic Fe-Al + Al2O3
1-10 m Al2O3
(for resistance to corrosion, MHD and Erosion)
150-180 m Intermetallic Fe-Al(for Tritium Permeation Resistance)
Ref: J. Konys et. al., FZK [4,5]
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Targeted MicrostructuresParameters for hot dipping: temperature at 700°C and dipping time of 30 s
Microstructure of hot dipped surface
The alloyed surface layer consists of brittle Fe2Al5, covered by solidified Al
Microstructure after heat treatment
F82H-mod.
Fe2Al5
AlFeAl
-Fe(Al)
F82H-mod.
HV 320
270
240
Heat treatment at 1040°C/0.5 h + 750°C/1 h and an applied pressure of >250 bar (HIPing) reduces porosity and transforms the brittle Fe2Al5-phase into the more ductile phases FeAl and -Fe(Al)Ref: J. Konys et. al., FZK [4,5]
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
HDA Setup - proposed Al2O3 - crucible
Sample
Al-melt
Furnace
Coating conditions [4,5]
Temperature: 700 – 750 °CMelt: Al or Al-Si (7-11% Si)Sample dimensions: 50 mm (l) x 30 mm (w) x 5 mm
Melting chamber
Holding chamber with protective environment
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
HDA PROCESS
Steel sample (sheet or
tube)Grinding Cleaning in
acetoneCoating, aq. flux-solution Pre-drying :
100°C
Glove-box (Ar-5%H2)
Hot-dip-aluminizing, 700°CCleaning in water
HIP-process (advanced process)
Heat Treatment (Standard process)
Coated sample
Ref: Voltrag, et. al. FZK [4,5]
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Challenges
Wettability of sample in Al melt Melt Composition (alloying, viz. Si) Surface Activation (fluxes etc.)
Case composition – tailored (Fe-Al) Post treatment (HIPing), dipping time, batch composition No porosities (HIPing), Case depth
Adherent Al2O3 layer on top Plasma oxidation process
Qualify for validation (performance related)
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Plans for development
Development of homogenous aluminized coating after HDA
Generation of desired compositional profile by heat treatment & plasma oxidation
Hot Isostatic Pressing of aluminized samples (To be worked out in collaboration with other national insitutes)
Hot Dip aluminizing700 – 750 C
Plasma Oxidation & H/T 1050 C
HIPing1050 C, 250 Bar
1 hrValidation
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Validation:
Pb-17Li Loop testing H2 / T permeation:- Initially the sample will be tested for
Hydrogen permeation- Susequently the sample will be
validated for Tritium permeation in Pb-Li environment
Ref: Schematic of Permeation testing facility at ENEA, Italy
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Present status
Design & generation of specs for furnace Fabrication & installation of furnace Preliminary trials for HDA – wettability &
uniformity Heat treatment optimization Characterization Hot Isostatic Pressing Validation
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Thank You
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
References:1) Design Description Document for Indian Lead Lithium cooled ceramic breeder
(LLCB) Blanket
2) G. W. Hollenberg et. al., Tritium / Hydrogen Barrier Development, June 1994, 3rd Intl. Symposium on Fusion Nuclear Technologies, LA, California
3) P.S. Korinko et. al., ‘Dev. of aluminide coatings for Hydrogen isotope permeation resistance’, Tritium 2001, Tsukaba, Japan, 11-16 Nov, 2001
4) J. Konys et. al., ITER TBM Project Meeting, UCLA, Feb 23-25, 2004.
5) J. Konys et. al., J. Nucl. Mat. 367-370 (2007) 1144-1149
6) H. Glasbrenner et. al., J. Nucl. Mat. 307-311 (2002) 1360-1363
BACK
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
Corrosion data
1
10
100
1.000
10.000
Me
tal
los
sR
[µm
/a]
700 750 800 850 900 950 1.000
Temperature T [K]
450 500 550 600 650 700
T [°C]
Correlation by Sannier et al.ML = 8·10 ·d [µm/a]9 0.875 -0.125·exp{-25690/1.98T}·v h
~20 µm/a
~151 µm/a
typical Picolo flow rate
experimental rangefor LAF steels in Picolo
80 - 100 µm/a
0.05 m/s
0.005 m/s
0.22 m/s
~553 µm/a
Eurofer 97 in Picolo at 550°Cextrapolation by first 3000 h
~ 500 µm/a
BACK
Ref: W. Krauss et. al., Intl. workshop on breeder blankets, RussiaJune, 2006
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
T (°C) VPS HDA CVD
300 450 3100 3100
350 400 2800 2100
400 380 1500 1600
450 380 2400 1300
pH2= 1 bar, steel: F82H-mod., Ref: J. Konys et. al. [4]
Results of permeation testing in H2–gas in different facilitiesat ENEA Brasimone, Italy (PERI, CORELLI)
Permeation Reduction Factors (PRF)
cancelled
BACK
N.I. Jamnapara, S. Mukherjee, P. M. Raole, E. RajendrakumarWS&FT ’08, 21-22 July, 2008
22-July-08IPR, Gandhinagar
WHY HIPPING?Microstructure after heat treatment
Heat treatment at 1040°C/0.5 h + 750°C/1 hincorporates the solidified Al and transforms the brittle Fe2Al5-phase into the more ductile
phases FeAl and -Fe(Al)
FeAl
-Fe(Al)
F82H-mod.
HV 320
270
240
Microstructure after HIP
FeAl
-Fe(Al)
F82H-mod.
HV 320
270
240
Heat treatment at 1040°C/0.5 h + 750°C/1 h and an applied pressure of >250 bar (HIPing) reduces porosity and transforms the brittle Fe2Al5-phase into the more ductile phases FeAl and -Fe(Al)BACK
Ref: J. Konys et. al. [4]