' Zr-Nb-Sn-Fe-X Evaluation of Corrosion and Mechanical Properties of Zr-Nb-Sn-Fe-X Alloys for Fuel Claddings,,, 15 36 LiOH 4 Zr-Nb-Sn-Fe-X. LiOH Zr-Nb-Sn-Fe-X, LiOH Zircaloy-4.. 47 52. Abstract The corrosion resistance of Zr-Nb-Sn-Fe-X alloys were evaluated by the autoclave tests under the environments of 36water, 36LiOH 7 ppm solution and 4steam. The mechanical properties of those alloys were also investigated by tensile tests and creep tests. The corrosion resistance of the alloys in the water and the LiOH solution showed similar behavior, while they are superior to that of Zircaloy-4 in LiOH solution. The alloys, which have much in alloying content, showed better properties in tensile strength and creep resistance due to alloying effect. The final heat treatment of the alloys at 47and 52has little differences in corrosion behavior but much in mechanical strength and creep strength because the heat treatment at 47has more dislocation barrier than that at 52. Key words : Corrosion resistance, Zirconium alloy, Zircaloy-4, Dislocation 1. 18, 6GWd/MtU, ph 7.4 ph
. Zircaloy-4. Zircaloy-4 creep Zilro [1-2] M5 [3] NDA[4] MDA[5]. K-Series Zr. Zr-Nb-Sn-Fe Zircaloy-4Zirlo. 47 52. 2. VAR(Vacuum Arc Remelting) 1 Zr-Nb- Sn-Fe 2gbutton. 1-7 torr Ar 4. 2-2..9 3 47 52. 22 12SiC H 2 O 5% + HNO 3 45% + HF 5% 36 LiOH 7ppm 36 autoclave4 autoclave. mounting, 22 12SiC HF 1% + HNO3 45% + H2O 45% etching 2. Knoop HMV-2 1g 1. Knoop. 68m, 3 TEM Twin Jet-Polisher. C2H5OH 9+ HClO 4 1, 45-4 1217V.1. TEM 2kV JOEL TEM TEM EDS. ASTM E8 INSTRON-455 4.
.9mm, (gauge length) 25mm 4 15MPa 24. 3.1. 3. 1247 2.5 (SR ) 52 2.5 (RX ) 36, LiOH 7ppm 36 4 21 Zircaloy-4 (Zry4) Zirlo (). 1Nb.4% Nb A1A2, 2Nb.8% Nb B1, B2, B3. A, B 36 36LiOH. 4 Zry4 Zirlo. PWR LiOH A, B Zirlo Zry4..2%-1%Nb Zr Nb [6], 1-5%Nb Zr-Nb Nb [7-8] Nb, A, B NbNb,. LiOH Zry4 6 A, B. A, B. A, B. 321 A, B SR RX. 36 36LiOH B2 RX SR 4 A1 RX SR. SR RX A, B. 3.2. 4A, B 1, 2 3 SRRX 2. 157 2. 2 1
. 3 1, 2 3 1, 2 47 SR 52 RX. TEM 5 SR RX. 6A, B 1,2 3 SR RX Knoop. 1 2. 2 1. 3 SR RX SR RX 5SR. 7 9. SR RX. SR 5. B2, B3 SR, RX. 5RX B2, B3. A, B SR RX TEM EDX, Sn. Zr-Sn Sn Sn A, B. 4. Zr-Nb-Sn-Fe 36 LiOH 4,. 1. 36 LiOH., 36LiOH Zry4 Zirlo. 2. 4 Zry4 Zirlo. 36 Zry4Zirlo Nb A1, A2 Zirlo.
3. 47 52 47, B2, B3.,. References [1] G. P. Sabol et al., "In-Reactor Corrosion Performance of ZIRLO and Zircaloy-4", ASTM STP 1245, (1994). [2] R. J. Comstock et al., "Influence of Processing Variables and Alloy Chemistry on the Corrosion Behavior of ZIRLO Nuclear Fuel Cladding", ASTM STP 1295, (1996). [3] Mardon, J.P., et al., "The M5 Fuel Rod Cladding", Avignon, Sept. 13-15, 1999 [4] K.Goto, S.Matsumoto, T.Murata, T.Miyashita, H.Anada, H.Abe, 1-8-1, Proceedings of 2 International Topical Meeting on LWR Fuel Performance, Park city, Utah, April 1-13, 2 [5] Yasuhiro Irisa, Sigemitsu Suzuki, Kenji Murai, R.Sabate, Ken Goto, J.M.Alonso, 1-7-1, Proceedings of 2 International Topical Meeting on LWR Fuel Performance, Park city, Utah, April 1-13, 2 [6] H.G. Kim, Y.S. Lim, M.Y. Wey and Y.H. Jeong: J. Kor. Inst. Met. & Mater., 37, (1999) 584 [7] V.F. Urbanic and R.W. Gilbert: Effect of microstructure on the corrosion of Zr-2.5Nb alloys, IAEA Technical committee meeting on fundamental aspects of corrosion of zirconium-based alloys for water reactor environments, Portland, Oregon, 11-15 Sept. 1989 [8] Meng, X. and Northwood, D.O.: ASTM STP 123, (1989) 478
Table 1. Chemical composition of the Zr-Nb-Sn-Fe-X alloys Group ID Composition Low Nb High Nb Reference Tube A1 A2 B1 B2 B3 ZRY Zr-.4Nb-.8Sn-xFe-xMn Zr-.4Nb-.8Sn-xFe-xMo Zr-.8Nb-.6Sn-xFe-xMo Zr-1.Nb-1.Sn-xFe-xCu Zr-1.5Nb-.4Sn-xFe-xCr ZIRLO Zircaloy-4 Table 2. Manufacturing processes of the the Zr-Nb-Sn-Fe-X alloys Manufacturing Steps Beta treatment Heat treatment condition 12 o C, 3min Hot rolling 59 o C, 3min Annealing 1 st cold rolling & Annealing 2 nd cold rolling & Annealing 59 o C, 3hr (A1, A2) (B1, B2, B3) 57 o C, 2h 57 o C, 3h 57 o C, 2h 57 o C, 3h 3 rd cold rolling & Final annealing SR: 47 o C, 2.5h RX: 52 o C, 2.5h SR: 47 o C, 2.5h RX: 52 o C, 2.5h ````
16 14 12 1 8 6 A1SR A1RX A2SR A2RX Zry4 36 o C WATER 4 2 2 18 16 14 12 1 45 4 2 4 6 8 1 12 14 16 18 2 22 8 6 4 2 A1SR A1RX A2SR A2RX Zry4 A1SR A1RX A2SR A2RX Zry4 Exporsure Time (Days) 4 o C Steam 2 4 6 8 1 12 14 16 18 2 22 Exporsure Time (Days) 36 o C LiOH 12 9 6 3 2 4 6 8 1 12 14 16 18 2 22 Exporsure Time (Days)
16 14 12 1 8 6 B1SR B1RX B2SR B2RX B3SR B3RX Zry4 36 o C WATER 4 2 2 18 16 14 12 1 2 4 6 8 1 12 14 16 18 2 22 8 6 B1SR B1RX B2SR B2RX B3SR B3RX Zry4 Exporsure Time (Days) 4 o C STEAM 4 2 45 42 39 36 1 8 6 4 2 4 6 8 1 12 14 16 18 2 22 B1SR B1RX B2SR B2RX B3SR B3RX Zry4 Exporsure Time (Days) 36 o C LiOH 2 2 4 6 8 1 12 14 16 18 2 22 Exporsure Time (Days)
1 9 8 7 SR RX 36 o C Water/21 days 6 5 4 3 2 1 A1 -- A2 -- B1 -- B2 -- PK1 -- Zry4 -- -- Specimen 2 18 16 14 SR RX 4oC STEAM / 21 days 12 1 8 6 4 2 A1 -- A2 -- B1 -- B2 -- PK1 -- Zry4 -- -- Specimen 42 45 SR RX 36 o C LiOH / 21 days 8 6 4 2 A1 -- -- A2 -- -- B1 -- -- B2 -- -- PK1 -- Zry4 -- -- Specimen
m
Knoop Hardness 1CR+57A 2CR+57A 3CR+47SR 3CR+52RX 7 SR at 47 o C Rx at 52 o C UTS, MPa 6 5 4 B1 A1 A2 B2 PK1 Alloys Tested at Room Temperature 5 45 SR at 47 o C Rx at 52 o C 4 UTS, MPa 35 3 25 2 B1 A1 A2 B2 PK1 Alloys Tensile-Tested at 4 o C
Creep Rate, x1e-7 %/s 1 1 1.8Nb.6SnFeMo(B1).4Nb.8SnFeMn(A1).4Nb.8SnFeMo(A2) 1.Nb1.SnFeCu(B2) 1.5Nb.4SnFeCr(B3) 46 48 5 52 54 Final Annealing Temperature, o C