Neutron as a daily tool towards the application to the steel - PowerPoint PPT Presentation

Neutron as a daily tool towards the application to the steel industry Masato OHNUMA Hokkaido University, Sapporo, Japan in collaboration with P.Kozikowski, T. Ishida, M. Furusaka (Hokkaido Univ.) B.S.Seong (KAERI, Korea ), J.Suzuki (CROSS, Japan) K. Suresh, Y.Oba (Kyoto Univ.) "CANS is usuful for pre-experiment & education." Only for them? CANS itself is useful and good enough for promoting materials science 1. "Unique information" accurate evaluation of main constituent element in nano-precipitates by Combined method of SAXS and SANS 2. "Easy & Quick": daily use of neutron as the first step of characterization by in-house compact neutron source 1

CANS activities in Japan at this moment Compact source is spreading in Japan JCANS Hokkaido Univ. from 1973 large facilities Tohoku Universit, planning J-PARC University of Tokyo, planning RIKEN ： started from 2012 (ex.3) reactor:JRR-3 Nagoya University, start soon (ex.1) Kyoto university, running Kyushu university, planning Ibaraki CANS start soon (ex.2) Sumijyu kensa Kyoto university research reactor KURRI (private company) 2

CANS activity in Japan ~ 1 st example, Nagoya Univ. NUANS ： Engineering test of BNCT & Engineering and science applications １） BNCT engineering test Electrostatic Acc. Sealed Li target （ IBA 2.8MeV, 42kW) Compact and low radioactive system Engineering feasibility of the BNCT system ２） Science ・ Engineering applications ： Be target Imaging (Power ＜ 4kW) project leader Profs Shimizu & Kiyanagi

CANS activity in Japan ~ 1 st example, Nagoya Univ. IBA Dynamitron accelerator Ep ： 1.9-2.8 MeV (variable) Ip ： 15mA 、 DC Size and weight ： 7.5 m × 2.8 m 、 6.5 ton High voltage Accelerator Quadrupole power supply ECR ion source Beam exit tube magnet SF6 gas container

CANS activity in Japan ~ 1 st example, Nagoya Univ. Beam profile observed during commissioning January of 2016 We got 2.8MeV, 11mA beam (~70%) Commissioning is continuing for stable operation FWHM X:31.8 mm The profile was Y:34.5 mm measured before setting the beam transport tube.

CANS activity in Japan ~ 2nd example, Ibaraki Pref. Project Team : Univ. of Tsukuba, KEK, JAEA, Hokkaido Univ., Ibaraki Pref., Mitsubishi Heavy Industry, etc. Concept ： Realization of BNCT with Safet y, , Sta Stable ble & & Easy Easy in a in a Hospital Hospital Research & Development; ● Compact & high power proton accelerator ● Neutron generator with neutron target device, moderator, Collimator and Shield applicable to NCT treatment. ● Treatment planning system, patient setting, neutron monitor & PG-SPECT. Moderator Beryllium Target System Collimator DTL RFQ Ion Source Proton Neutron Shield Proton Accelerator Neutron generator

CANS activity in Japan ~ 2nd example, Ibaraki Pref. ＋ RFQ + DTL Type Linac Ion Source + LEBT RFQ ＋ DTL Type Linac Type Proton Energy 8MeV Peak Current 50mA >5mA （ Max.10mA ） Average Current Beam plus 1msec. Duty 20% >40kW （ Max. 80kW ） Power to Target Klystron Length: <7m, Footprint: <50m 2 Dimension

CANS activity in Japan ~ 3rd example, RIKEN, already in use RANS (RIK IKEN Accelerator-driven compact neutron source) compact neutron source for practical use Proton linac, (commercially sold accelerator) (1.5 M.US$) Ep=7MeV Ip<100 μA maximum averaged current Δτ ： 10- 180μs pulse width of proton (30μs→ modified) Fr ： 20-180Hz repetition rate of proton project leader is Dr. Otake 1. Industrial use – iron and steel- Imaging ： Corrosion and water movement A) neutron Alloy Steel "Atsushi Taketani, et al ： ISIJ International Vol. 57, No. 1 (2017)

RANS (RIK IKEN Accelerator-driven compact neutron source) compact neutron source for practical use B)Engineering diffraction ： texture evolution, austenite volume fraction austenite volume fraction texture evolution volume Volume fraction from fraction from RANS the size diffraction 6.7 ± 0.8% 8.3% 17.4 ± 0.8% 19.1% 2minutes each diffraction measurements Y. Ikeda, et al Nucl. Instr. Meth. A833 (2016) 61-67 2. Social safety- Non-destructive inspection for social infrastructures, bridges, roads Success of the observation of air hole and steel bar position through Accelerator for RANS2 is coming Jan 2017 thick concrete 2.49MeV proton RANS2 N Air hole RANS3 Air hole position Steel Bar position

Neutron as a daily tool towards the application to the steel industry CANS itself is useful and good enough for promoting materials science 1. "Unique information" accurate evaluation of main constituent element in nano-precipitates by Combined method of SAXS and SANS 2. "Easy & Quick": daily use of neutron as the first step of characterization by in-house compact neutron source 10

we are in " nano-tech age" ! high-Q region in SAS is important Capacirter Fuel cell magnetic field sensor (battery) (J.Phys.Chem.C, 117(2013), (Polymer 52(2011), 98-106) (J.Appl.Phys. 82(1997),5642-5646 JAEA Tohoku Univ. 12003-12009) Univ. of Tokyo grafted nafion Solar cell (J.Phys D:Appl.Phys. 47(2014), #435102) RIEM 3 10 -1 ) 2 Intensity (cm -4 10 q but today, focus on the steels as examples 1 10 5 PbSe – ZnSe 4 3 substrate temp. 2 0 10 1 11 2 3 4 5 6 7 8 9 2 3 0 10 -1 ) q (nm

Why steel, too old? Structural Materials are still under developing ! constructed in 1887 – 1889 1 ９５７ – 1 ９５８ ２００８ – ２０１２ height ３３３ m height ６３４ m height ３２４ m ４０００ t (steel) ３２０００ t ７３００ t (wrought iron!) ２４０ N/mm 2 ４００ N/mm 2 160~220N/mm 2 ７００ N/mm 2 (gain tower) 0.3~2wt%C 0.05~0.25wt%C Mn, Ni, Mo addition ~0.1%C microstructure control by alloying and processing

Quantitative Evaluation of microstructure is important ! example of SAS application: Size and number density of oxide in ODS steels Acta Materia., 57, 5571-5581(2009) 9wt%Cr-0.13C-0.35Y 2 O 3 -(0.2~0.4)Ti-(1~2.4)W-(0.08~0.15)ex.O cladding tube for fast breeding reactor feature low swelling rate high creep strength konwn relation between composition and propeties structure of oxide is Y 2 Ti 2 O 7 unknown size and number density composition of Y 2 Ti 2 O 7 (composition of Fe) 13

Conventional use of SAS, size and number density of ODS steel Intensity = （ Dr ) 2 ・ ( number density) ・ volume 2 ・ ( form factor) 2 width of the profile intensity of profiles Dr depends on the phase known ！ Dr Y2Ti2O7 = r Y2Ti2O7 - r matix log ( I(q) ) [cm -1 ] size & number density number SANS density 1.9W-0.46Ti 0.11Ex.O N(cm -3 ) D ave (nm) V f average size of nano-oxide 2.0W-0.21Ti 2.4 ± 5% 1.1x10 18 1.9W-0.46Ti,0.11Ex.O 0.8% 1150º 0.08Ex.O C 2.4 ± 5% 9.6x10 17 2.0W-0.35Ti,0.08Ex.O 2.4W-0.21Ti 0.7% 1200ºC 0.12Ex.O 2.0W-0.35Ti extrude@1200 ℃ 2.5 ± 5% 7.3x10 17 0.6% q [nm -1 ] √f 0.08Ex.O s = const. 0.9W-0.21Ti 2.6 ± 5% 6.5x10 17 2.0W-0.21Ti,0.08Ex.O 0.6% 1.4W-0.21Ti 0.13Ex.O R 2.5 ± 5% 5.8x10 17 1.4W-0.21Ti,0.08Ex.O 0.5% = const. √(NR) 0.08Ex.O 1.9W-0.21Ti 4.5 ± 5% 1.3x10 17 2.4W-0.21Ti,0.12Ex.O 0.6% 0.15Ex.O 5.5 ± 5% 7.4x10 16 0.9W-0.21Ti,0.13Ex.O 0.7% 5.4 ± 5% 9.6x10 16 1.9W-0.21Ti,0.15Ex.O 0.6% 14

new way to get compositional information: Combination of SAXS & SANS intensity = （ Dr ) 2 x number density x( volume x form factor ) 2 composition determining factor of Intensity determined by microstructure ： no difference in SAXS and SANS one of them should be known !  ratio between SAXS and SANS r = n a c a b i D r = r - r matrix → cancelled out i i n a : number density of atom ， c a : atomic fraction ， information of composition b i : scattering length different dependence on atomic number ! ฀ ฀ SAXS N b for neutron [fm] Cr Fe C b for X-ray [fm] SANS atomic number 15 Each of SAXS and SANS cannot determine composition, but together, they can !

Combined use of SAXS and SANS ： accuracy is independent of size way to use #1 ： phase determination from candidate 8 different heat ODS steels SAXS I SAXS / I SANS = 40 ± 4 Cr 23 C 6 TiC Y 2 TiO 5 Y 2 O 3 Cr 2 O 3 Y 2 Ti 2 O 7 SANS Dr SAXS 2 / Dr SANS 2 4.6 16 48 60 69 40 way to use #2 ： difference from equilibrium substitute for Y x < 0.2 for (Y 1-x Fe x ) 2 Ti 2 O 7 ; ~ 4at% substitute for Ti x < 0.15 for Y 2 (Ti 1-x Fe x ) 2 O 7 ; ~ 3at% Odetta et al., JOM, 2010 substitute for O x < 0.1 for Y 2 Ti 2 (O 1-x Fe x ) 7 ; ~ 6at% 16

How to characterize compositions of heterogeneities smaller than 1 nm powerful for observing partition of alloying (minor) elements TEM-EDX Atom Probe electron beam 10 〜 100nm atomic resolution (in depth) evaporation aberration effect from matrix accurate comp. effect is large for main elements elements below 1~2 nm heterogeneity How to observe partition of main elements combined use of SANS & SAXS sensitivity independent of size possible to discuss main elements （ in this case, Fe) No other techniques make it possible 17