- Email: [email protected]
martensitic steel, F82H
Fusion Engineering and Design xxx (xxxx) xxx–xxx
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Effect of hydrogen on corrosion properties of reduced activation ferritic/ martensitic steel, F82H ⁎
Motoki Nakajima , Takashi Nozawa, Hiroyasu Tanigawa National Institute for Quantum and Radiological Science and Technology, Aomori, Japan
A R T I C LE I N FO
A B S T R A C T
Keywords: Reduced activation ferritic/martensitic steel Flow-accelerated corrosion Environmental strength High-temperature water Hydrogen
Reduced activation ferritic/martensitic (RAFM) steel, e.g., F82H, is the leading candidate structural material for fusion blanket. Of many blanket concepts, the water-cooled ceramic breeder blanket is an attractive concept because of its compactness and its compatibility with the technologies which using high-temperature water as coolant in conventional light water reactor. For tritium breeding, it is necessary to manage the corrosion of F82H by controlling not chemicals but hydrogen and oxygen in the cooling water. Understanding the effects of oxygen and hydrogen on corrosion property was therefore required for the blanket design. This work aims to investigate the corrosion behavior of F82H in high-temperature water with hydrogen added. Based on the results of the corrosion test, it is speculated that hydrogen addition expected no considerable change of the flow-accelerated corrosion (FAC). In contrast, it was found that the number of cycles to fracture was decreased in the hightemperature water in comparison to the fatigue test at room temperature in air.
1. Introduction
2. Experimental procedures
Water cooled ceramic breeder (WCCB) concept is a primary option for the ITER Test Blanket Module (TBM) and Japanese DEMO blankets [1–3]. The concept is attractive for its compatibility with the conventional technologies of pressurized water reactors (PWR). In the blanket, the pressurized water of 15.5 MPa at a temperature ranging from 558 to 598 K is used as the coolant. The water chemistry of coolants such as dissolved oxygen (DO) and dissolved hydrogen (DH) concentrations attract attention for determining corrosion allowance for structural material. Although the structural material is required to be as thin as possible for tritium breeding, it should withstand the internal pressure of 17.1 MPa which multiplied operating pressure of 15.5 MPa by safety factor of 1.1. Considering these requirements, the assessment of corrosion behavior was necessary to optimize wall thickness. However, available data on the corrosion of reduced activation ferritic/martensitic steel (RAFM) in a high-temperature water environment is limited [4–8]. In either case, they reported the corrosion properties in static water condition. Moreover, the effects of water flow and the estimation method of the corrosion of the actual flow channel from the disk test results have not yet been addressed. In this study, corrosion behavior of F82H in a low-DO and hydrogen added to water which simulates the conventional light water reactor condition was investigated to accumulate the corrosion data for blanket design.
The material used in this study was Japanese RAFM, F82H BA-07. The water chemical condition, such as dissolved oxygen (DO), dissolved hydrogen (DH), and pH was same in each test. The DO, DH and pH were < 5 ppb, 3.5 ppm and 7˜9 at room temperature, respectively, for every experiment. The FAC test was performed using a rotating disk specimen (O.D. = 275 mm, I.D. = 130 mm, thickness = 3 mm). The circumferential velocity on the specimen outer edge and inner edge were 5.0 m/s and 3.1 m/s, respectively. The FAC tests were conducted at 543 K under the pressure of 6.3 MPa. The test pressure is lower than the blanket operation pressure, but the effect of test pressure was ignored because it was known that the effect of pressure on corrosion was small [4,9]. After the FAC test, the weight change due to corrosion was measured using a precision balance. The corroded surfaces and specimen crosssections were observed by using a scanning electron microscope (SEM) to understand the mechanism of weight change. Surface corrosion products were examined using SEM, electron probe micro-analyzer (EPMA) and X-ray diffractometer (XRD). The corrosion fatigue test was performed under 0.6% of the total strain range and 0.0004%/sec of the strain rate with a triangle waveform at 573 K under the pressure of 13 MPa. The stress corrosion cracking (SCC) initiation and propagation tests are performed in the same autoclave of corrosion fatigue test. SCC
⁎
Corresponding author. E-mail address: [email protected] (M. Nakajima).
https://doi.org/10.1016/j.fusengdes.2019.03.064 Received 5 October 2018; Received in revised form 6 March 2019; Accepted 11 March 2019 0920-3796/ © 2019 Published by Elsevier B.V.
Please cite this article as: Motoki Nakajima, Takashi Nozawa and Hiroyasu Tanigawa, Fusion Engineering and Design, https://doi.org/10.1016/j.fusengdes.2019.03.064
Fusion Engineering and Design xxx (xxxx) xxx–xxx
M. Nakajima, et al.
Fig. 3. Effect of the dissolved oxygen (DO) on the flow-accelerated corrosion (FAC) property.
obtained from cross-sectional EPMA analysis, the static specimen has a two-layer structure of an outer oxide mainly formed as iron oxide and an inner layer oxide composed of chromium and iron. In contrast, it can be seen that there is no outer oxide in the flow corrosion specimens. Considering these results, the continuous dissolution of iron ions because of no outer oxide may lead to the weight loss of flow corrosion specimen. It was likely that the reason why there was no outer oxide was oxide dissolution, exfoliation, and inhibition of reprecipitate of iron ions dissolved from the matrix. At this moment, details are still unclear, and further research of flow corrosion mechanism of RAFM is necessary. Fig. 5 shows the thickness reduction in deaerated hydrogen-added water plotted against the time. This reduction in thickness was estimated from the weight change before and after descaling and using the density of F82H (7.86 g/cm3). The reduction in thickness increases according to the parabolic law with increasing time. By applying a parabolic approximation, the thinning amount W is empirically obtained as follows:
Fig. 1. Schematic drawing of the reverse U-bend (RUB) test specimen (unit: mm).
Fig. 2. Schematic drawing of the wedge opening loading (WOL) test specimen (unit: mm).
W= 0.149 t
(1)
Calculating the reduction in thickness from the Eq. (1) considering 10 years operation yields 44 μm, and there is sufficient margin to compare with 0.4 mm of the corrosion allowance of the conventional design of Japanese ITER-TBM [12].
initiation and propagation properties were evaluated by the reverse Ubend (RUB) test [10] and the wedge opening loading (WOL) test [11]. Schematic drawing of these specimen were shown in Figs. 1 and 2. The initial stress intensity factor of WOL specimen was 30 MPa m . The exposure times of RUB and WOL specimens were 1491 h. After these tests, the surface of RUB specimen and the crack surface of WOL specimen were observed by SEM.
3.2. Corrosion fatigue property Fig. 6 shows the fatigue-life curve for corrosion fatigue. The results obtained from room temperature, 573 K and 673 K in the air were also plotted in this figure for comparison [13]. The corrosion fatigue property in air shows no significant difference, but the fatigue life in hightemperature water drastically decreased in comparison to the fatigue test in the air. The Japan Society of Mechanical Engineers (JSME) Codes for nuclear power generation facilities: environmental fatigue evaluation method for nuclear power plants (2009) [14] has defined the environmental fatigue correlation factors as the value obtained by dividing the fatigue life in the air with a particular strain amplitude by the fatigue life in the water with the same strain amplitude. Based on this definition, the environmental fatigue correlation factor for RAFM is 19. Calculating the factors of low alloy steel and austenitic stainless steel by using the evaluation formula of the JSME code in the test condition of this study were estimated to be 3 and 12, respectively. Therefore, corrosion fatigue property of F82H was inferior to carbon and low-alloy steel, and it equivalent or slightly lower to the austenitic stainless steel.
3. Results and discussion 3.1. Flow-accelerated corrosion property Fig. 3 shows the weight change before and after the corrosion test plotted as a function of exposure time. The results obtained from static corrosion test were also plotted in this figure as a reference [9]. As shown in Fig. 3, under static condition and condition with DO concentration of 8 ppm, the weight increased after the corrosion test. On the other hand, under the condition of deaerated hydrogen addition and DO concentration of 20 ppb, the weight tended to decrease with increasing the time up to 1000 h. Since there is no significant difference in weight change between conditions of hydrogen addition and DO concentration of 20 ppb, it is considered that the weight was decreased by the same mechanism. Fig. 4 shows the results of surface observation by the SEM and crosssectional EPMA analysis of the specimens after the corrosion test. If DO was 20 ppb or less, regardless of hydrogen addition, blocky oxides were observed on the surface of the static corrosion specimen, but such an oxide was not observed in the flow corrosion specimens. From the result
3.3. Stress corrosion cracking property Fig. 7 shows the surface observation results before and after RUB test. Although the surface of the specimen was black discolored and 2
Fusion Engineering and Design xxx (xxxx) xxx–xxx
M. Nakajima, et al.
Fig. 4. Effects of the dissolved hydrogen (DH) and water flow on oxide morphology.
Fig. 7. Surface observation results before and after the reverse U-bend (RUB) test.
Fig. 5. Time dependency of reduction in thickness.
Fig. 8. Fracture surface after the wedge opening loading (WOL) test. Fig. 6. Effect of test environment on corrosion fatigue property.
the pressure of 23.5 MPa and DO concentration of 0.2 ppm. Miwa et al. also reported the SCC susceptibility of F82H at 513, 573and 603 K in oxygenated (DO = 10 ppm or 40 ppb) water, and it was concluded that SCC does not occur in those environments [7]. Considering these results, although further data accumulation of SCC is needed, it can be expected that SCC susceptibility of F82H was quite small in the broad range of water condition and temperature.
corroded, the SCC crack was not occurred up to 1500 h. Fig. 8 shows the fracture surfaces after WOL test. Compared with the surface oxide morphology at notch-tip and crack-tip, there was no significant difference and also no evidence of SCC propagation. Hirose et al. reported the SCC susceptibility of F82H in super critical pressurized water by using slow strain rate test method [5]. They revealed that F82H did not demonstrated SCC in the temperature of 563–823 K, 3
Fusion Engineering and Design xxx (xxxx) xxx–xxx
M. Nakajima, et al.
4. Conclusions
[4] K. Shiba, et al., JAERI-Tech 97-038, (1997). [5] T. Hirose, K. Shiba, M. Enoeda, M. Akiba, Corrosion and stress corrosion cracking of ferritic/martensitic steel in super critical pressurized water, J. Nucl. Mater. 367–370 (2007) 1185–1189. [6] D. De Meis, E. Lo Piccolo, R. Torella, Corrosion Resistance of RAFM Steels in Pressurized Water for Nuclear Fusion Applications, ENEA-RT-2017-04 (2017). [7] Y. Miwa, S. Jitsukawa, T. Tsukada, Stress corrosion cracking susceptibility of a reduced-activation martensitic steel F82H, J. Nucl. Mater. 386–388 (2009) 703–707. [8] J. Lapeña, F. Blázquez, D. Gómez Briceño, P. Fernández, Corrosion of F82H Modified and Eurofer 97 Martensitic Steels in Water With Additives, DFN/ME-35/ IE-01 (2001). [9] M. Nakajima, T. Hirose, H. Tanigawa, M. Enoeda, Corrosion properties of F82H in flowing high temperature pressurized water, J. Plasma Fusion Res. SERIES 11 (2015) 69–72. [10] JIS G 0511, Stress Corrosion Cracking Testing of Metals and Alloys Using Reverse Ubend Test Method, (2014). [11] Society of Materials Science, Standardized Stress Corrosion Cracking Test Methods, Japan, 1985. [12] H. Tanigawa, M. Enoeda, H. Tanigawa, 2. Development targets of reduced activation ferritic /martensitic steel -application to fusion blanket, J. Plasma Fusion Res. 87 (2011) 163–166. [13] H. Tanigawa, E. Gaganidze, T. Hirose, M. Ando, S.J. Zinkle, R. Lindau, E. Diegele, Development of benchmark reduced activation ferritic/martensitic steels for fusion energy applications, Nucl. Fusion 57 (2017) 092004. [14] JSME S NF1, Codes for Nuclear Power Generation Facilities –Environmental Fatigue Evaluation Method for Nuclear Power Plants-, (2009).
1 It was confirmed that the specimen weight after the corrosion test in hydrogen-added water was decreased as similar to the case of corrosion experiments in deaerated water. However, the thickness reduction is sufficiently small and not to be a serious problem with the conventional design. 2 It was found that the corrosion fatigue life was 1/19 compared with that obtained in air. 3 According to the results obtained from RUB and WOL tests, the SCC initiation and propagation did not occur up to 1500 h. It was speculated that the SCC susceptibility of F82H was low. References [1] M. Akiba, M. Enoeda, S. Tanaka, Overview of the TBM R&D activities in Japan, Fusion Eng. Des. 85 (2010) 1766–1771. [2] T. Hirose, H. Tanigawa, A. Yoshikawa, Y. Seki, D. Tsuru, K. Yokoyama, K. Ezato, S. Suzuki, M. Enoeda, M. Akiba, Recent status of fabrication technology development of water cooled ceramic breeder test blanket module in Japan, Fusion Eng. Des. 86 (2011) 2265–2268. [3] Y. Nomoto, S. Suzuki, K. Ezato, T. Hirose, D. Tsuru, H. Tanigawa, T. Hatano, M. Enoeda, M. Akiba, Structural concept of Japanese solid breeder test blanket modules for ITER, Fusion Eng. Des. 81 (2006) 719–724.
4
Contents lists available at ScienceDirect
Fusion Engineering and Design journal homepage: www.elsevier.com/locate/fusengdes
Effect of hydrogen on corrosion properties of reduced activation ferritic/ martensitic steel, F82H ⁎
Motoki Nakajima , Takashi Nozawa, Hiroyasu Tanigawa National Institute for Quantum and Radiological Science and Technology, Aomori, Japan
A R T I C LE I N FO
A B S T R A C T
Keywords: Reduced activation ferritic/martensitic steel Flow-accelerated corrosion Environmental strength High-temperature water Hydrogen
Reduced activation ferritic/martensitic (RAFM) steel, e.g., F82H, is the leading candidate structural material for fusion blanket. Of many blanket concepts, the water-cooled ceramic breeder blanket is an attractive concept because of its compactness and its compatibility with the technologies which using high-temperature water as coolant in conventional light water reactor. For tritium breeding, it is necessary to manage the corrosion of F82H by controlling not chemicals but hydrogen and oxygen in the cooling water. Understanding the effects of oxygen and hydrogen on corrosion property was therefore required for the blanket design. This work aims to investigate the corrosion behavior of F82H in high-temperature water with hydrogen added. Based on the results of the corrosion test, it is speculated that hydrogen addition expected no considerable change of the flow-accelerated corrosion (FAC). In contrast, it was found that the number of cycles to fracture was decreased in the hightemperature water in comparison to the fatigue test at room temperature in air.
1. Introduction
2. Experimental procedures
Water cooled ceramic breeder (WCCB) concept is a primary option for the ITER Test Blanket Module (TBM) and Japanese DEMO blankets [1–3]. The concept is attractive for its compatibility with the conventional technologies of pressurized water reactors (PWR). In the blanket, the pressurized water of 15.5 MPa at a temperature ranging from 558 to 598 K is used as the coolant. The water chemistry of coolants such as dissolved oxygen (DO) and dissolved hydrogen (DH) concentrations attract attention for determining corrosion allowance for structural material. Although the structural material is required to be as thin as possible for tritium breeding, it should withstand the internal pressure of 17.1 MPa which multiplied operating pressure of 15.5 MPa by safety factor of 1.1. Considering these requirements, the assessment of corrosion behavior was necessary to optimize wall thickness. However, available data on the corrosion of reduced activation ferritic/martensitic steel (RAFM) in a high-temperature water environment is limited [4–8]. In either case, they reported the corrosion properties in static water condition. Moreover, the effects of water flow and the estimation method of the corrosion of the actual flow channel from the disk test results have not yet been addressed. In this study, corrosion behavior of F82H in a low-DO and hydrogen added to water which simulates the conventional light water reactor condition was investigated to accumulate the corrosion data for blanket design.
The material used in this study was Japanese RAFM, F82H BA-07. The water chemical condition, such as dissolved oxygen (DO), dissolved hydrogen (DH), and pH was same in each test. The DO, DH and pH were < 5 ppb, 3.5 ppm and 7˜9 at room temperature, respectively, for every experiment. The FAC test was performed using a rotating disk specimen (O.D. = 275 mm, I.D. = 130 mm, thickness = 3 mm). The circumferential velocity on the specimen outer edge and inner edge were 5.0 m/s and 3.1 m/s, respectively. The FAC tests were conducted at 543 K under the pressure of 6.3 MPa. The test pressure is lower than the blanket operation pressure, but the effect of test pressure was ignored because it was known that the effect of pressure on corrosion was small [4,9]. After the FAC test, the weight change due to corrosion was measured using a precision balance. The corroded surfaces and specimen crosssections were observed by using a scanning electron microscope (SEM) to understand the mechanism of weight change. Surface corrosion products were examined using SEM, electron probe micro-analyzer (EPMA) and X-ray diffractometer (XRD). The corrosion fatigue test was performed under 0.6% of the total strain range and 0.0004%/sec of the strain rate with a triangle waveform at 573 K under the pressure of 13 MPa. The stress corrosion cracking (SCC) initiation and propagation tests are performed in the same autoclave of corrosion fatigue test. SCC
⁎
Corresponding author. E-mail address: [email protected] (M. Nakajima).
https://doi.org/10.1016/j.fusengdes.2019.03.064 Received 5 October 2018; Received in revised form 6 March 2019; Accepted 11 March 2019 0920-3796/ © 2019 Published by Elsevier B.V.
Please cite this article as: Motoki Nakajima, Takashi Nozawa and Hiroyasu Tanigawa, Fusion Engineering and Design, https://doi.org/10.1016/j.fusengdes.2019.03.064
Fusion Engineering and Design xxx (xxxx) xxx–xxx
M. Nakajima, et al.
Fig. 3. Effect of the dissolved oxygen (DO) on the flow-accelerated corrosion (FAC) property.
obtained from cross-sectional EPMA analysis, the static specimen has a two-layer structure of an outer oxide mainly formed as iron oxide and an inner layer oxide composed of chromium and iron. In contrast, it can be seen that there is no outer oxide in the flow corrosion specimens. Considering these results, the continuous dissolution of iron ions because of no outer oxide may lead to the weight loss of flow corrosion specimen. It was likely that the reason why there was no outer oxide was oxide dissolution, exfoliation, and inhibition of reprecipitate of iron ions dissolved from the matrix. At this moment, details are still unclear, and further research of flow corrosion mechanism of RAFM is necessary. Fig. 5 shows the thickness reduction in deaerated hydrogen-added water plotted against the time. This reduction in thickness was estimated from the weight change before and after descaling and using the density of F82H (7.86 g/cm3). The reduction in thickness increases according to the parabolic law with increasing time. By applying a parabolic approximation, the thinning amount W is empirically obtained as follows:
Fig. 1. Schematic drawing of the reverse U-bend (RUB) test specimen (unit: mm).
Fig. 2. Schematic drawing of the wedge opening loading (WOL) test specimen (unit: mm).
W= 0.149 t
(1)
Calculating the reduction in thickness from the Eq. (1) considering 10 years operation yields 44 μm, and there is sufficient margin to compare with 0.4 mm of the corrosion allowance of the conventional design of Japanese ITER-TBM [12].
initiation and propagation properties were evaluated by the reverse Ubend (RUB) test [10] and the wedge opening loading (WOL) test [11]. Schematic drawing of these specimen were shown in Figs. 1 and 2. The initial stress intensity factor of WOL specimen was 30 MPa m . The exposure times of RUB and WOL specimens were 1491 h. After these tests, the surface of RUB specimen and the crack surface of WOL specimen were observed by SEM.
3.2. Corrosion fatigue property Fig. 6 shows the fatigue-life curve for corrosion fatigue. The results obtained from room temperature, 573 K and 673 K in the air were also plotted in this figure for comparison [13]. The corrosion fatigue property in air shows no significant difference, but the fatigue life in hightemperature water drastically decreased in comparison to the fatigue test in the air. The Japan Society of Mechanical Engineers (JSME) Codes for nuclear power generation facilities: environmental fatigue evaluation method for nuclear power plants (2009) [14] has defined the environmental fatigue correlation factors as the value obtained by dividing the fatigue life in the air with a particular strain amplitude by the fatigue life in the water with the same strain amplitude. Based on this definition, the environmental fatigue correlation factor for RAFM is 19. Calculating the factors of low alloy steel and austenitic stainless steel by using the evaluation formula of the JSME code in the test condition of this study were estimated to be 3 and 12, respectively. Therefore, corrosion fatigue property of F82H was inferior to carbon and low-alloy steel, and it equivalent or slightly lower to the austenitic stainless steel.
3. Results and discussion 3.1. Flow-accelerated corrosion property Fig. 3 shows the weight change before and after the corrosion test plotted as a function of exposure time. The results obtained from static corrosion test were also plotted in this figure as a reference [9]. As shown in Fig. 3, under static condition and condition with DO concentration of 8 ppm, the weight increased after the corrosion test. On the other hand, under the condition of deaerated hydrogen addition and DO concentration of 20 ppb, the weight tended to decrease with increasing the time up to 1000 h. Since there is no significant difference in weight change between conditions of hydrogen addition and DO concentration of 20 ppb, it is considered that the weight was decreased by the same mechanism. Fig. 4 shows the results of surface observation by the SEM and crosssectional EPMA analysis of the specimens after the corrosion test. If DO was 20 ppb or less, regardless of hydrogen addition, blocky oxides were observed on the surface of the static corrosion specimen, but such an oxide was not observed in the flow corrosion specimens. From the result
3.3. Stress corrosion cracking property Fig. 7 shows the surface observation results before and after RUB test. Although the surface of the specimen was black discolored and 2
Fusion Engineering and Design xxx (xxxx) xxx–xxx
M. Nakajima, et al.
Fig. 4. Effects of the dissolved hydrogen (DH) and water flow on oxide morphology.
Fig. 7. Surface observation results before and after the reverse U-bend (RUB) test.
Fig. 5. Time dependency of reduction in thickness.
Fig. 8. Fracture surface after the wedge opening loading (WOL) test. Fig. 6. Effect of test environment on corrosion fatigue property.
the pressure of 23.5 MPa and DO concentration of 0.2 ppm. Miwa et al. also reported the SCC susceptibility of F82H at 513, 573and 603 K in oxygenated (DO = 10 ppm or 40 ppb) water, and it was concluded that SCC does not occur in those environments [7]. Considering these results, although further data accumulation of SCC is needed, it can be expected that SCC susceptibility of F82H was quite small in the broad range of water condition and temperature.
corroded, the SCC crack was not occurred up to 1500 h. Fig. 8 shows the fracture surfaces after WOL test. Compared with the surface oxide morphology at notch-tip and crack-tip, there was no significant difference and also no evidence of SCC propagation. Hirose et al. reported the SCC susceptibility of F82H in super critical pressurized water by using slow strain rate test method [5]. They revealed that F82H did not demonstrated SCC in the temperature of 563–823 K, 3
Fusion Engineering and Design xxx (xxxx) xxx–xxx
M. Nakajima, et al.
4. Conclusions
[4] K. Shiba, et al., JAERI-Tech 97-038, (1997). [5] T. Hirose, K. Shiba, M. Enoeda, M. Akiba, Corrosion and stress corrosion cracking of ferritic/martensitic steel in super critical pressurized water, J. Nucl. Mater. 367–370 (2007) 1185–1189. [6] D. De Meis, E. Lo Piccolo, R. Torella, Corrosion Resistance of RAFM Steels in Pressurized Water for Nuclear Fusion Applications, ENEA-RT-2017-04 (2017). [7] Y. Miwa, S. Jitsukawa, T. Tsukada, Stress corrosion cracking susceptibility of a reduced-activation martensitic steel F82H, J. Nucl. Mater. 386–388 (2009) 703–707. [8] J. Lapeña, F. Blázquez, D. Gómez Briceño, P. Fernández, Corrosion of F82H Modified and Eurofer 97 Martensitic Steels in Water With Additives, DFN/ME-35/ IE-01 (2001). [9] M. Nakajima, T. Hirose, H. Tanigawa, M. Enoeda, Corrosion properties of F82H in flowing high temperature pressurized water, J. Plasma Fusion Res. SERIES 11 (2015) 69–72. [10] JIS G 0511, Stress Corrosion Cracking Testing of Metals and Alloys Using Reverse Ubend Test Method, (2014). [11] Society of Materials Science, Standardized Stress Corrosion Cracking Test Methods, Japan, 1985. [12] H. Tanigawa, M. Enoeda, H. Tanigawa, 2. Development targets of reduced activation ferritic /martensitic steel -application to fusion blanket, J. Plasma Fusion Res. 87 (2011) 163–166. [13] H. Tanigawa, E. Gaganidze, T. Hirose, M. Ando, S.J. Zinkle, R. Lindau, E. Diegele, Development of benchmark reduced activation ferritic/martensitic steels for fusion energy applications, Nucl. Fusion 57 (2017) 092004. [14] JSME S NF1, Codes for Nuclear Power Generation Facilities –Environmental Fatigue Evaluation Method for Nuclear Power Plants-, (2009).
1 It was confirmed that the specimen weight after the corrosion test in hydrogen-added water was decreased as similar to the case of corrosion experiments in deaerated water. However, the thickness reduction is sufficiently small and not to be a serious problem with the conventional design. 2 It was found that the corrosion fatigue life was 1/19 compared with that obtained in air. 3 According to the results obtained from RUB and WOL tests, the SCC initiation and propagation did not occur up to 1500 h. It was speculated that the SCC susceptibility of F82H was low. References [1] M. Akiba, M. Enoeda, S. Tanaka, Overview of the TBM R&D activities in Japan, Fusion Eng. Des. 85 (2010) 1766–1771. [2] T. Hirose, H. Tanigawa, A. Yoshikawa, Y. Seki, D. Tsuru, K. Yokoyama, K. Ezato, S. Suzuki, M. Enoeda, M. Akiba, Recent status of fabrication technology development of water cooled ceramic breeder test blanket module in Japan, Fusion Eng. Des. 86 (2011) 2265–2268. [3] Y. Nomoto, S. Suzuki, K. Ezato, T. Hirose, D. Tsuru, H. Tanigawa, T. Hatano, M. Enoeda, M. Akiba, Structural concept of Japanese solid breeder test blanket modules for ITER, Fusion Eng. Des. 81 (2006) 719–724.
4