Evaluation of high temperature tensile and greep properties of light water reactor coolant piping materials for severe accident analyses

Harada, Yuhei; Maruyama, Yu; Maeda, Akio*; Chino, Eiichi; Shibazaki, Hiroaki*; Kudo, Tamotsu; Hidaka, Akihide; Hashimoto, Kazuichiro; Sugimoto, Jun

Journal of Nuclear Science and Technology, 37(6), p.518 - 529, 2000/06

https://doi.org/10.3327/jnst.37.518

no abstracts in English

The evaluation of material base standard of ODS ferritic stainless steel core component for fast breeder reactors

Mizuta, Shunji; ;

JNC TN9400 2000-048, 28 Pages, 2000/04

JNC-TN9400-2000-048.pdf:0.64MB

ODS (Oxide Dispersion Strengthened) ferritic-martainsitic steels are one of the most prospective cladding materials for advanced fast breeder reactors, since they are expected to have excellent swelling resistance and superior high temperature strength due to the finely distributed stable oxide particles(YO). Properties and the tentative strength equations for ODS ferritic-martainsitic were proposed on the basis of the latest data to apply to the feasibility study of the sodium coolant MOX fuel plant. The items of equations are follows. (1)creep rupture strength (2)correction factor of creep rupture strength (in Na and in reactor) (3)outer surface eorrosion (Na) (4)inner surface corrosion (in MOX fuel pin) (5)thermal conductivity

Ultra-High temperature strength properties on Mod.9Cr-1Mo steel

; Yoshida, Eiichi; Aoto, Kazumi

JNC TN9400 2000-042, 112 Pages, 2000/03

JNC-TN9400-2000-042.pdf:8.55MB

A sodium-water reaction drove from the single tube break in steam generator of FBR might overheat labor tubes rapidly under internal pressure loadings. lf the temperature of tube wall becomes too high, it has to be evaluated that the stress of tube does not exceed the material strength limit to prevent the propagation of tube rupture. This study clarified the tensile and creep properties of Mod.9Cr-1Mo steel at ultra-high temperature which will be used in evaluation of the tube burst by sodium-water reaction. The strain rates for tensile test are from 10%/min to 10%/sec, and creep-rupture time is maximum 277sec. The range of test temperature is 700C to 1300C. The main results obtained were as follows; (1)The evaluation data on the relationship between tensile strength and strain rate and creep-rupture strength in shorter time on Mod.9Cr-1Mo steel were acquired. (2)Short-term mechanical properties of Mod.9Cr-1Mo steel were evaluated based on the results of tensile and creep-rupture tests up to 1300C. As a result of the evaluation, recommended equation of creep-rupture strength in the short-term was proposed. (3)Tensile and creep-rupture strength of Mod.9Cr-1Mo steel tube showed the value which was higher than the 2 1/4Cr-1Mo steel, and it was proven to have the superior properties.

Material test data of SUS304

; *

JNC TN9450 2000-001, 1370 Pages, 1999/10

JNC-TN9450-2000-001.pdf:117.18MB

This report summarizes the material test data of SUS304. Numbers of the data are as follows. (1)Tensile tests 738 (Post-irradiation: 250, others: 488) (2)Creep tests 434 (Post-irradiation: 89, others: 345) (3)Fatigue tests 612 (Post-irradiation: 60, others: 552) (4)Creep-fatigue tests 200 (Post-irradiation: 40, others: 160) This report consists of the printouts from "the structural material data processing system".

Simulation of creep test on 316FR stainless steel in sodium environment at 550

Satmoko, A.*;

JNC TN9400 99-035, 37 Pages, 1999/04

JNC-TN9400-99-035.pdf:1.54MB

In sodium environment, materia1 316FR stainless steel risks to suffer from carburization. In this study, an analysis using a Fortran program is conducted to evaluate the carbon influence on the creep behavior of 316FR based on experimental results from uni-axial creep test that had been performed at temperature 550C in sodium environment simulating Fast Breeder Reactor condition. As performed in experiments, two parts are distinguished. At first, elastic-plastic behavior is used to simulate the fact that just before the beginning of creep test, specimen suffers from load or stress much higher than initial yield stress. In second part, creep condition occurs in which the applied load is kept constant. The plastic component should be included, since stresses increase due to section area reduction. For this reason, elastic-plastic-creep behavior is considered. Through time carbon penetration occurs and its concentration is evaluated empirically. This carburization phenomena are assumed to affect in increasing yield stress, decreasing creep strain rate, and increasing creep rupture strength of material. The model is capable of simulating creep test in sodium environment. Material near from surface risks to be carburized. Its material properties change leading to non-uniform distribution of stresses. Those layers of material suffer from stress concentration, and are subject to damage. By introducing a damage criteria, crack initialization can thus be predicted. And even, crack growth can be evaluated. For high stress levels, tensile strength criterion is more important than creep damage criterion. But in low stress levels, the latter gives more influence in fracture. Under high stress, time to rupture of a specimen in sodium environment is shorter than in air. But for stresses lower than 26 kgfmm, the time to rupture of creep in sodium environment is the same or little longer than in air. Quantitatively, the carburization effect at ...

Mechanical properties on high Cr-Mo steels at elevated temperature (V); Tensile, creep and relaxation properties of Mod.9Cr-1Mo steel plate and tube for steam generator.

; *; ; Yoshida, Eiichi;

PNC TN9410 94-261, 143 Pages, 1994/06

PNC-TN9410-94-261.pdf:2.54MB

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.

Evaluation of the same heat hastelloy XR as the material used for high-temperature components of the High-Temperature Engineering Test Reactor, 2nd report; Evaluation of short-time strength properties for base metal

Tsuji, Hirokazu; *; Nakanishi, Tsuneo*; *; Nakajima, Hajime

JAERI-M 93-209, 64 Pages, 1993/10

JAERI-M-93-209.pdf:2.64MB

no abstracts in English

None

*; *; *; *; *; *; *

PNC TJ9009 91-004, 149 Pages, 1991/08

PNC-TJ9009-91-004.pdf:24.83MB

None

Mechanical properties on high Cr-Mo steels at elevated temperature (III); Creep properties of high Cr-Mo steel forgings (250280mm t)

; ; Yoshida, Eiichi;

PNC TN9410 91-099, 106 Pages, 1991/02

PNC-TN9410-91-099.pdf:5.72MB

This stady was performed in order to confirm the influence of sampling method on Creep properties of 9Cr-Mo steel forgings which are promising as candidate materials for steam generator of large scale fast breeder reactor. This results are to be reflected on fundation of materials strength standard. Test materials are four kinds of 9Cr-Mo steel forgings (thickness:250280mmt) such as Mod.9Cr-1Mo (F4, F8 heats), 9Cr-1Mo-Nb-V(G3 heat), 9Cr-2Mo (H6 heat) steels. Results obtained are summarized as follows. (1)In order to evaluation of fundamental material properties, creep-rupture data on three kinds of 9Cr-Mo steel forgings such as Mod.9Cr-1Mo, 9Cr-2Mo and 9Cr-1Mo-Nb-V steels was obtained up to 10,000 hours. (2)The Mod.9Cr-1Mo steel exhibited most excellent creep-rupture strength and the 9Cr-2Mo steel was the worst among the three. (3)The effect of the sampling location of specimens on creep strength was not significant for Mod.9Cr-1Mo steel. But for 9Cr-1Mo-Nb-V steel and 9Cr-2Mo steel, longer creep rupture time was observed with spcimens taken from just below the center of the surface with direction of L, and shorter creep rupture time was observed for those taken from t/2 thickness at the center with direction of Z. (4)Creep strength of 9Cr-2Mo steel was lower than that of Mod.9Cr-1Mo (F4, F8)and 9Cr-1Mo-Nb-V steel. But rupture elongation and reduction of area of 9Cr-2Mo steel was greater than hat of other three materials, irrespective of the sampling location of specimens.

Creep fatigue behavior of SUS 304 Stainless steel tested in sodium at 550C

*

PNC TN9410 90-086, 47 Pages, 1990/05

PNC-TN9410-90-086.pdf:1.76MB

Since stainless steels like SUS 304 and SUS 316 tend to be carburized in sodiun, the grain boundary near surface may be degraded due to carbides precipitation. In order to clarify the effect of the grain boundary degradation upon creep fatigue strength, long term creep fatigue tests of SUS304 stainless steel were performed in carburized sodium, 0btained results are summarized as follows: (1)Creep fatigue life in carburized sodium was nearly equal to that in air, in spite of the fact that severe carburization and carbides precipitation on grain boundary were observed on tested specimen surface. (2)Creep fatigue life calculated using usual linear damage summation rule showed good agreement with experimental results, (3)It was revealed that crack initiation life in carburized sodium was almost the same as that in air, although crack initiated on degraded grain boundary in carburized sodium. (4)The above fact supplies an evidence to justify the concept that creep fatigue crack initiation life in sodium is longer than 1/20 of failure life obtained using small specimens in air, which is basic assumption of our creep fatigue evaluation method. It is conjectured from this study that FBR grade SUS316 stainless steel will show almost the same creep fatigue life as that in air, however, a few creep fatigue tests of FBR grade SUS316 in carburized sudium will be necessary to clarify this conjecture.