Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
; Kano, Shigeki; ; Tachi, Yoshiaki; Hirakawa, Yasushi; Yoshida, Eiichi
PNC TN9410 98-021, 68 Pages, 1998/02
Engineering ceramics have excellent properties such as high strength, high hardness and high heat resistance compared with metallic matelials. To apply the ceramic in fast reactor environment, it is necessary to evaluate the sodium compatibility and the influence of sodium on the mechanical properties of ceramics. In this study, the influence of high temperature sodium on the mechanical properties of sintered ceramics of conventional and high purity Al
O
, SiC, SiAlON, AlN and unidirectional solidified ceramics of AlO/YAG eutectic composite were investigated by means of flexure tests. Test specimens were exposed in liquid sodium at 823K and 923K for 3.6Ms. There were no changes in the flexural strength of the conventional and high purity AlO, AlN and AlO/YAG eutectic composite after the sodium exposure at 823K. On the contrary, the decrease in the flexural strength was observed in SiC and SiAlON. After the sodium exposure at 923K, there were also no changes in the flexural strength of AlN and AlO/YAG eutectic composite. In the conventional and high purity AlO and SiC, the flexural strength decreased and signs of grain boundary corrosion were detected by surface observation. The flexural strength of SiAlON after the sodium exposure at 923K increased instead of severe corrosion. In the specimens those showed no changes in the flexural strength, further exposure in sodium is needed to verify whether the mechanical properties degrade or not. For SiAlON, it is necessary to clarify the reason for the increased strength after the sodium exposure at 923K.
Sawada, Kota; Maruyama, Koichi; Komine, Ryuji; Nagae, Yuji
PNC TN9410 98-018, 32 Pages, 1998/02
Mod.9Cr-1Mo steel has a martensitic lath structure. Recovery of the lath structure takes place hl the course of creep. Microstructural degradation due to the recovery results in the acceleration of creep rate and the subsequent failure of a specimen. Change of lath width during creep of the steel was quantitatively investigated to propose a residual life assessment methodology based on the recovery process. Since the steel was tempered at 1053K, the lath structure is thermally stable at the testing temperatures (848K
923K). However, recovery of lath structure readily takes place during creep, indicating that the recovery is induced by creep deformation. Lath width 
increases with creep strain and saturates to a value 
determined by creep stress. The increase of is faster at a higher stress and temperature. A normalized ehange in lath width, 
/, was introduced to explain the variation of lath growth rate with creep stress and temperature. is the change in lath width from the initial value 
, and is the difference between and . / is uniquely related to creep strain 
and the relationship is independent of creep stress as well as ereep temperature. This /- relationship obtained by an accelerated creep test at a higher temperature or stress is applicable to any creep condition including service conditions of engineering plants. Creep strain can be evaluted from the measurement of / based on the /- relationship. A creep curve under any creep condition can readily be calculated by creep data of the steel. Combining these information one can assess residual life of a structural component made of the steel.
Aoto, Kazumi; ; ; ; ; Hirakawa, Yasushi
PNC TN9450 97-016, 860 Pages, 1997/06
This report describes the check of the thermocouple well at the inlet of the intermediate heat exchanger(IHX) of C-loop of the secondary heat transfer system of the prototype fast breeder reactor Monju, regarding the sodium leak accident of the thermocouple well at the outlet of the IHX of the same loop of the secondary heat transfer system of the same plant Monju. Various tests and inspections were performed to check damages at the part with rapid diameter change of the thermocouple well where stress concentration may occur, and to get the information about the integrity of the welded part between the thermocouple well and the attachment. The thermocouple well, the rapid diameter change part, larger and smaller part, respectively, of the thermocouple well, and welded part between the thermocouple well and the attachments were examined as written below. (1)Accurate measurement of the dimension. (2)Vibration test by tapping the thermocouple well. (3)Non destructive testing at some points. (4)Chemical composition analysis. (5)Microscopic observation of metalogical structure. (6)Detailed observation around the rapid diameter change part. (7)Hardness test. (8)Research on corrosion at the clearance. (9)Structure strength test of the thermocouple well. (10)Bending test of the thermocouple's sheath at high temperature.
Aoto, Kazumi; ; ; ; ; Hirakawa, Yasushi
PNC TN9420 97-007, 786 Pages, 1997/06
PNC-TN9420-97-007.pdf:311.86MB
The results of the research on the damaged thermocouple well which caused the sodium leak accident at the outlet of the C-loop intermidiate heat exchanger (IHX) of the secondary heat transfer system of the prototype fast breeder reactor Monju are described in this report. A lot of tests, inspections, observations and measurements were carried out to confirm that the thermocouple well and its attachments to the pipe including welded part are normal by checking the possibility of weld failure or corrosion at the clearance which may cause the damage of the thermocouple well, and to get information of the dimensions relating the estimation of the leaked sodium volume and the leakage path, etc. These tests, etc., were performed for the thermocouple well except the fractured surface, the thermocouple well, the welded parts between the thermocouple well and the attachment, and between the attachment and the outlet pipe, etc., as written below. (1)Accurate measurement of the dimension. (2)Inspection to check the fixing condition between the thermocouple well and the attachment. (3)Measurement of the residual stress. (4)Non destructive testing at some points. (5)Chemical composition analysis. (6)Microscopic observation of metalogical structure at the welded part. (7)Hardness test. (8)Research on corrosion at the clearance. (9)Structure strength test of the thermocouple well. (10)Bending test of the thermocouple's sheath at high temperature.
Sawada, Kota; Maruyama, Koichi; Komine, Ryuji; Nagae, Yuji
PNC TN9410 97-035, 41 Pages, 1997/03
Several microstructural changes take place in a material during the course of creep. These changes can be a measure of creep life consumption. In this paper, microstructural changes in Mod.9Cr-1Mo steel were studied in order to examine their ability as the measure of crecp life consumption. Macroscopic structural changes, such as void growth, rotation of lath structure toward the tensile axis and elongation of grains, are evident only in the necked portion of ruptured specimens. These macroscopic structural changes are not useful for creep life assessment. Lath width increases and dislocation density within lath decreases with increasing creep duration. These changes in dislocation substructure start in the early stage of creep life, and cause the increase of strain rate in the tertiary creep stage. The lath width and the dislocation density reach a stationary value before rupture. The stationary values are independent of temperature, and uniquely related to creep stress normalized by shear modulus. The extent of these microstructural changes are greater at lower stresses under which the material is practically used. These facts suggest that the lath width and the dislocation density within lath can be a useful measure of creep life consumption. Hardness of crept specimens is closely related to the lath width and the dislocation density within lath. The changes of these microstructural features can be evaluated by the measurement of handness.
Sawada, Kota*; Maruyama, Koichi*; Komine, Ryuji; Nagae, Yuji
Tetsu To Hagane, 83(7), p.466 - 471, 1997/00
None
; Aoto, Kazumi;
PNC TN9450 97-012, 75 Pages, 1996/11
This report described the results of tensile and creep tests under a high temperature with the welded joints of liner plate (SM400B) used in SHTS cells of leaked sodium storage system of "NONJU plant". Results obtained are summarized as follows. (1)Foundmental high temperature strength characteristics data of the welded Joints were acquired. (2)There is no effect of heat treatment and cut-out direction on tensile strength and rupture elongation of liner plate. (3)The rupture ductility (rupture elongation and reduction of area) is lower than one of the base metal. Especially, rapidly droped in the temperature over 800 
C. (4)The creep strength of welded joint is almost same as one of the based metal. It will be estimated the effect of change of the micro-structure on the ductility. (5)Generally speaking, two phases of 
phase and 
phase intermingled exist under about 800C, and phases transform to the phase under about 900C over Ac3 transformation point. Then the grain boundary in HAZ, begin to grow, and the intergranular failure appears in over 900C. The results will be applied to evaluate the stractural integrity of SHTS cells of leaked sodium storage system of "MONJU plant". (SHTS ; Secondary Heat Transfer System)
; Aoto, Kazumi;
PNC TN9450 97-011, 83 Pages, 1996/11
This report described results of tensaile and creep tests under a high temperature with the base metal of the liner plate (SM400B) used in the SHTS cells of leaked sodium storage system of "MONJU plant". Results obtained are summarized as follows. (1)Foundmental high temperature strength characteristics data of the material of the liner plate was acquired. (2)There is no effect of heat treatment and cut-out direction on tensile strength and rupture elongation of the liner plate. (3)The tensile strength and rupture elongation rapidly change from 800C to 1000 C, because there were the recovery by a change of micro-structure in the temperature range near the Ac3 transformation point. Uniform elongation was approximately from 10% to 20%, without its value in 700C. (4)Elastic modulus and constitutional equation for elastic-plastic stress-strain behavior and the equation for the creep strain behavior were proposed. The results will be applied to evaluate the structural integrity of the SHTS cells of leaked sodium storage system of "MONJU plant". (SHTS ; Secondary Heat Transfer System)
Aoto, Kazumi; ;
PNC TN9410 97-037, 51 Pages, 1996/11
The basic material properties of a rolled steel for welded structure (present standard name is SM400B, old standard name SM41B) which is used as the liner plate in SHTS cells of "Monju plant". Based on the material testing data for evaluation of structural integity of the liner during sodium leakage are tentatively proposed. Main basic material properties are shown as follows. (1)The 0.2% offset yield stress (lower yield point). (2)The ultimate tensile strength. (3)The modulus of the longitudinal elasticity. (4)Static stress-strain relation. (Physical property in Ludwik equation). (5)The creep strain. (6)The linear thermal expansion coefficient. (7)The density. (8)A specific heat. (9)The thermal conductivity.
PNC TN9450 96-016, 629 Pages, 1996/06
In order to advancement in materials strength standard on elevated temperature design guide of the Demonstration Farst Reactors and evaluation method of materials strength behavior, this report are presented about the tensile and Creep, fatigue and creep fatigue and relaxation test, effect properties of 316FR steel, based on the R&D result obtained throgh the activities of materials tests. Contents of the data sheet are as follows; (1)Material; 316FR steel (Base metal.) (2)Test method and Number of data; Tensile test 105 points; Creep test 99 points; Fatigue test 104 points; Creep fatigue test 18 points; Relaxation test 6 points (3)Environment; in Air And thire data are arrengement by the stractural materials data system (SMAT).
Aoto, Kazumi; ; ; ; ; Hirakawa, Yasushi
PNC TN9410 97-076, 29 Pages, 1996/06
This report describes the check of the thermocouple well at the inlet of the intermediate heat exchanger (IHX) of C-loop of the secondary heat tansfer system of the prototype fast breeder reactor Monju, regarding the sodium leak accident of the thermocouple well at the outlet of the IHX of the same loop of the secondary heat transfer system of the same plant Monju. Various tests and inspections were performed to check damages at the part with rapid diameter change of the thermocouple well where stress concentration may occur, and to get the information about the integrity of the welded part between the thermocouple well and the attachment. The thermocouple well, the rapid diameter change part, larger and smaller part, respectively, of the thermocouple well, and welded part between the thermocouple well and the attachments were examined as written below. (1)Accurate measurement of the dimension. (2)Vibration test by tapping the thermocouple well. (3)Non destructive testing at some points. (4)Chemical composition analysis. (5)Microscopic observation of metalogical structure. (6)Detailed observation around the rapid diameter change part. (7)Hardness test. (8)Research on corrosion at the clearance. (9)Structure strength test of the thermocouple well. (10)Bending test of the thermocouple's sheath at high temperature.
; ; *; *
PNC TN9450 96-002, 173 Pages, 1996/01
In order to advancement in materials strength standard on elevated temperature design guide of the FBRs and evaluation method of materials strength behavior, this report are presented about the creep properties of FBR grade 316 (Abbreviation 316FR), based on the R&D results obtained through the activities of material tests. Contents of the data sheet are as follows; (1)Material : 316FR (Weld Joint, Weld Metal) (2)Test environment : In air (3)Test temperature : 550C650C (4)Test method : According to JIS and FBR Metallic Materials Test Method (5)Number of deta : 71 points
; ; *; *
PNC TN9450 96-001, 70 Pages, 1996/01
In order to advancement in materials strength standard on elevated temperature design guide of the FBRs and evaluation method of materials strength behavior, this report are presented about the tensile properties of FBR grade 316 (Abbreviation 316FR), based on the R&D results obtained through the activities of material tests. Contents of the data sheet are as follows; (1)Material : 316FR (Weld Joint , Weld Metal) (2)Test temperature : R.T650C (3)Test method : According to JIS and FBR Metalic Materials Test Method (4)Number of data : 40 points
; ; *; *; *
PNC TN9450 95-013, 70 Pages, 1995/08
In order to advancement in materials strength standard on elevated temperature design guide of the FBRs and evaluation method of materials strength behavior, this report are presented about the low-cycle fatigue and high-cycle fatigue, creep fatigue, low-strain rate effect properties of 316FR, besed on R&D result obtained through the sctivities of materials tests. Contents of the data sheet are as follows ; (1)Material ; 316FR(Base metal.) [B6 Heat 1,000
1,00025t (Plate)] [B7 Heat 1,0001,00050t (Plate)] [B8 Heat 1,0001,00025t (Plate)] [MC Heat 1,0001,00025t (Plate)] (2)Environment ; in Air (3)Test temperature ; R,T,100,200,300,400,450,500,550,600,650,700,800C Strain rate ; 1.0%/sec , 0.1%/sec, 0.01%/sec, 0.001%/sec, 0.0001%/sec, (4)Strain hold time ; 0.1hr, 1.0hr (5)Strain range ; 0.38%1.86% (6)Number of data ; 108 points And thire data are arrengement by the stractural materials date system (SMAT).
*; *; *; *
ASME PVP96 & ICPVP8, 0 Pages, 1995/00
None
1MoAoto, Kazumi; ; Ueno, Fumiyoshi; Kawasaki, Hirotsugu; Wada, Yusaku
Nuclear Engineering and Design, 153(1), p.97 - 110, 1994/12
Times Cited Count：56 Percentile：96.55(Nuclear Science & Technology)None
; *; ; Yoshida, Eiichi;
PNC TN9410 94-261, 143 Pages, 1994/06
In this study, tensile, creep and relaxation test in air were performed in order to examine the mechanical properties of Mod.9Cr-1Mo steel which is a candidate material for once throuth type steam generator of large scale fast breeder reactor. Tested materials were plate(12mmt) simulating heat exchenger tube and heat exchenger tube of Mod.9Cr-1Mo steel and 9Cr-2Mo steel was also tested as reference material. Results obtained are summarized as follows. (1)Tensile properties (a)Ultimate tensile strength and 0.2% yield strength of Mod.9Cr-1Mo steels were higher than the tentative Su and Sy values of the design allowable stress in the test temperature below 600C. (b)Ultimate tensile strength of Mod.9Cr-1Mo steels plate and tube were higher than that of 9Cr-2Mo Steels. (3)The difference in ultimate tensile strength and 0.2% yield strength between steel plate and tube could not be found in these tests. (2)Creep properties (a)Creep rupture strength of Mod.9Cr-1Mo steel plate and tube was higher than the tentative S
value of the design creep-rupture stress intensity at 500600C, and this tendency is significant in the range of longer rupture time. (b)For the relation between steady creep rate and creep rupture time, steady creep rates obtained in this study coincided well with the 
of tentative creep strain equation. (c)Creep rupture strength of Mod.9Cr-1Mo steel plate and tube was higher than that of 9Cr-2Mo steel. (3)Relaxation properties (a)In the strain range of 0.10.5%, stress rapidly relaxed during the short hold time, and stress relaxation tended to be saturate beyond 50hours. These relaxation stresses became large in higher temperature and higher strain level. (b)Stress relaxation behavior was predicted approximately by tentative creep equation of Mod.9Cr-1Mo steel. The analysis of these test results is continued to develop of evaluation method of material strength.
Furukawa, Tomohiro; ; Yoshida, Hidekazu;
PNC TN9410 93-042, 56 Pages, 1993/02
Mod.9Cr-1Mo steel is a candidate material of once-through type steam generators for the Fast Breeder Reactors, and it is required to clarify low-cycle fatigue properties in air at high temperature on this material for structural design. So the tests were carried out for three heats (12mmt plate, 25mmt plate and 250mmt forged) on conditions that temperature is 450650C and strain range is 0.41.2%. Results obtained are su㎜araized as follows. (1)For cyclic stress-strain behavior of Mod.9Cr-1Mo steel cyclic hardening was. observed in the early stage, and after that changed to softening to failure. The behavior was similar to normalized and tempered 2.25Cr-1Mo steel. (2)Low-cycle fatigue strength of Mod.9Cr-1Mo steel in air was remarkably higher than that of 2.25Cr-1Mo steel, and almost same as much as that of SUS304 steel. Moreover, fatigue life of Mod.9Cr-1Mo steel was longer than that of 9Cr-2Mo or Low C-9Cr-1Mo-Nb-V steel under low strain conditions. (3)In the case of Mod.9Cr-1Mo forged steel, the influence of the sampling position and direction of specimens was not effective. These results were reflected to prepare of tentative material strength standard in 1992.
Wada, Yusaku; ; Kato, Shoichi; Seki, Seiichi
Residual Stresses - III, Vol.2, p.1519 - 1524, 1992/00
None
