1. 3 rd LEADER International Workshop ”Design and safety analysis of Alfred” Pisa/Bologna, Sept. 4 th -7 th, 2012 LFR material issues Peter Szakálos, Surface and Corrosion Science, KTH email: szakalos@kth.se P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

2. Outline -Fundamentals about oxidation and implications to LFR -Developement of oxidation resistant alloys for LFR (KTH/Sandvik) -Liquid metal embrittlement -Creep/Irradiation - LFR Material issues – condensed summary P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

3. High Temperature Oxidation and Corrosion Basically very simple: For a given environment, the metal should form either a protective oxide or no product at all. Or in other words: Kinetics (slow) or Thermodynamics (immunity) P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

4. Overview of protective oxides at 900  C Oxidation rate Cr Oxide thickness P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

5. ”If cations move sufficiently to avoid development of stress and anions move in suficiently to avoid the development of cavities and porosity, a highly resistant film should develop” U.R. Evans 1963. Then the interesting question rises how to realize the simultaneous movements in both directions? Oxidation kinetics P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

6. P. Kofstad: OAE: Oxygen Active (dissociative) Element RE, REM Y,Ce,La,Hf,Th,Zr Most problematic! Balanced oxide growth P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

8. Ferritic stainless and austenitic stainless 304, 316. Effect of hydrogen through 1mm interconnect at 8-900  C in fuel cells. ( Z. Yang et al, publ. 2003-2007, M. Ziomek-Moroz et al, publ. 2003 and 2004) Spallation due to hydrogen penetration: H 2 /air Reference sample: air/air The effect of hydrogen on oxidation P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

9. G. Hultquist, B. Tveten, E. Hörnlund Oxidation of Metals, 54(1/2), 2000, p.1-10. Oxidation of Cr in 20 mbar O 2 at 900  C The effect of hydrogen on oxidation P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

10. G. Hultquist and P. Szakalos, KME-report 401, 2010 SIMS-profiles through the oxide layer of a commercial FeCrAlY-alloy exposed to a two step isotope labelled oxygen exposure at 900°C (20 mbar 16 O 2 followed by 20 mbar 18 O 2 ). Thin surface oxide 10 wt-ppm H 30 wt-ppm H Thick surface oxide I.e. the optimal RE-addition in a steel depends on the exposure environment! ( Depth ) The hydrogen effect on oxidation- unbalanced growth P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

11. The effect of hydrogen on oxidation -Hydrogen in the metallic substrate results in a more defective oxide (protons/water vapor) -In particular, increased outward metal-cation transport (unbalanced growth) Hydrogen is released when metals is oxidised by water vapour -Steam side oxidation in superheaters affects the corrosion on the combustion side P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

12. GENIUS: Corrosion tests and development of FeCr(Ni)Al- steels P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012 Industrial supervisor, Bo Jönsson, Sandvik Heating Technology AB (Spinodal decomposition)

13. Austenites and 9Cr-ferrites Exposure in LBE 10 -6 wt-% dissolved oxygen (Ar-H 2 O-H 2 ). Cross section: 550°C, 500hr, static LBE P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

14. HAYNES 230 Ni-22Cr-14W-2Mo-0.05C Exposed 4000h in liquid lead, 550°C. Oxygen content in the liquid lead: 10 -7 wt-% O (Gas phase: Ar-H 2 O-H 2 ) Ni-base HT-alloys P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

15. OverviewAluminiumOxygen IronLeadChromium 15 550°C 10 -7 wt-% O 2500 h Kanthal APMT (ODS) 22Cr-5Al-3Mo-RE - superior corrosion performance! P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

16. Choise of steels for fast neutron reactors P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

17. Designing new FeCrAl-alloys and coatings Good enough? P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

18. 10Cr-8Al-RE 10Cr-6Al-RE 10Cr-4Al-RE FeCrAl experimental alloys 10Cr-6A l 550°C 10 -7 wt-% O 2500 h No RE P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

19. Austenite (15-15Ti) exposed in lead and H 2 O/H 2 -gas phase respectively Lead Gas phase 550°C 10 -7 wt-% O 2500 h P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

20. LPPS-FeCrAlY coating + GESA IV Original FeCrAlY coating 1.4970 cladding (15-15Ti) concentration profile (Ni, Co, Fe)CrAlY X X High solubility in PbHigh activation under irradiation Georg Müeller, Karlsruhe Institute of Technology (KIT), ELECTRA Workshop 6-7 March Stockholm 2012 P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012 Advantages: industrial coating process homogeneous element distribution smooth surface after GESA treatment free of pores after GESA treatment perfect bonding after GESA treatment GESA treated FeCrAlY coating 1.4970 cladding

21. Liquid Metal Embrittlement (LME) in 9Cr-steel (T91) exposed to LBE -Physisorption from gaseous lead in the crack -Reduction in surface energy and bonding -Adsorption induced slip Z. Hadjem-Hamouche, T. Auger, I. Guillot, Corrosion Science 51 (2009) CCT sample in LBE. Gasphase: He-4%H 2 (PLC-effect) P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012 Data evaluated from tensile tests with constant displacement rate. Crack growt rate evaluated with a CCD-camera.

22. LFR requirement: 650  C,100MPa,10 4 h ”An addition of Zr recovers creep lifetime of Al-added ODS steels by two orders of magnitude” FeCrAl creep properties P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

23. Neutron irradiation performance of reference structural materials (XT-ADS) J. Henry, Ph. Dubuisson CEA. Helimnet/Demetra Workshop, Berlin March 2010 T91 irradiated to 78 dpa (T test : 25°C) Austenite AISI 316L: -Yield stress incresses by several hundred MPa under irradiation at ~330°C, while the UE (uniform elongation) drops to negligible values by ~5-10 dpa. Saturation of tensile properties occur at ~10 dpa; the fracture mode is ductile even at high dose. Irradiation-induced hardening is highest in the range [300-350°C]. - Fracture toughness values remain high at 3 dpa exposure (250-300°C irr. T) but should drop with increasing dose. 9Cr-ferrite, T91: -Irradiation at ~330°C induces a huge hardening together with a complete loss of ductility (doses>~40dpa) and a cleavage type fracture mode. Low activation steels (clean steels) exibit lower hardening and retain a ductile behaviour up to 80 dpa. At Temperatures > 400°C, there is little irradiation-induced hardening. - As expected from the tensile behaviour, T91 impact properties are drasticly modified by irradiation at ~330°C (very large DBBT shift, catastrophic decrease of USE). Above ~400°C, 9Cr steels exibit moderate DBTT shifts. Little fracture toughness data is available in the temperature range of interest. - 9Cr martensitic steels exibit good dimensional stability with an irradiation creep modulus (swelling) lower than that of austenitic steels. P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

24. Oxidation kinetics in air + 10% H 2 O 20Cr-25Ni-1.5MoNbTiN heat-resistant austenitic stainless (Nippon steel) 20Ni-14Cr-2.5Al-NbC New ”RE”? P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

25. Steel type:Weakness: 9Cr Ferrite/MartensiteOxidation, Fracture toughness in lead Austenites, type 316LSwelling, Oxidation Fe20CrAlSpinodal decomposition Fe(12±2)CrAlCreep? Fracture toughness? FeNi(15±5)CrAl-ODS Austenite? LFR material issues - condensed summary: P. Szakálos, 3 rd LEADER International Workshop, Pisa/Bologna Sept. 4 th -7 th, 2012

26. ( Alumina former: Ti 2 AlC )

27. Rolls Royce gas turbine coatings YSZ, Yttria Stabilized ZrO 2