Fatigue behavior on weldment of austenitic stainless steel for ITER vacuum vessel

Nishi, Hiroshi; Eto, Motokuni; Tachibana, Katsumi; Koizumi, Koichi; Nakahira, Masataka; Takahashi, Hiroyuki*

Fusion Engineering and Design, 58-59, p.869 - 873, 2001/11

https://doi.org/10.1016/S0920-3796(01)00490-2

no abstracts in English

Mechanical properties of type 316L stainless steel welded joint for vacuum vessel of ITER, 2; Neutron irradiation tests and post-irradiation experiments

Saito, Shigeru; Fukaya, Kiyoshi; Ishiyama, Shintaro; Amezawa, Hiroo; Yonekawa, Minoru; Takada, Fumiki; Kato, Yoshiaki; Takeda, Takashi; Takahashi, Hiroyuki*; Koizumi, Koichi

JAERI-Tech 2001-035, 81 Pages, 2001/06

JAERI-Tech-2001-035.pdf:18.91MB

no abstracts in English

Microstructural assessment of damaged materials in FBR assessment of creep damage in weldment

Momma, Yoshio*; *; ; ; ; Aoto, Kazumi

JNC TN9400 2000-044, 22 Pages, 2000/03

JNC-TN9400-2000-044.pdf:1.37MB

ln the past the microstructural observation was mostly applied to understand the materials behavior qualitatively in R&D of the new materials and the life prediction for the fast breeder reactor components. However, the correlation between the changes in properties and microstrutures must be clarified to ensure the structural integrity. Particularly we are interested in the method to correlate the long-term properties and microstructural changes at high temperatures. The current research is to quantify the changes in microstructure of the weld metal for the welded structure of the reactor vessel. ln this research we have conducted creep testing of the weld metals at 823 and 873K up to 37,000h. Two types of the weld metals (16Cr-8Ni-2Mo and 18Cr-12Ni-Mo) were subjected to the creep testing. Based on the areas of the precipitates, the microstructural characterization with time and creep damage was attempted. The creep strength of the 16Cr-8Ni-2Mo weld metal is lower than that of the 18Cr-12Ni-Mo one at higher stresses, shorter times. But there is a trend toward to become similar strength with lower stresses and increasing times. The creep-rupture ductility of the 16Cr-8Ni-2Mo weld metal is superior to that of the 18Cr-12Ni-Mo one. The creep-rupture takes place at the interface of the sigma () phases precipitated in the delta () ferrites at 823K lower stresses and 873K. The amount of precipitates in the 16Cr-8Ni-2Mo weld metal is smaller than that in the 18Cr-12Ni-Mo one at each temperature and stress. Also it is apparent that the amount of the precipitates is primarily responsible to the decomposition of the phase, because the amount of the residual ferrites measured by the Magne-Gauge reduces with times. Using the Larson-Miller parameter it was possible to correlate the amount of the precipitates linearly with the LMP values.

Creep strength of Hastelloy XR welded joints

Tachibana, Katsumi; Nishi, Hiroshi; Eto, Motokuni;

JAERI-Tech 99-024, 65 Pages, 1999/03

JAERI-Tech-99-024.pdf:3.01MB

no abstracts in English

Post-irradiation weldability of type 316 stainless steel

Watanabe, Katsutoshi; Hamada, Shozo; Kodaira, Tsuneo; Hishinuma, Akimichi

ASM Conference on Welding and Joining Science and Technology, p.615 - 619, 1997/03

no abstracts in English

High-temperature strength test of the liner material (II); High-temperature tensile and creep property of SM400B welded joint material

; Aoto, Kazumi;

PNC TN9450 97-012, 75 Pages, 1996/11

PNC-TN9450-97-012.pdf:25.58MB

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)

Development of creep-fatigue evaluation method for welde structures considering metallurgical and geometrical discontinuities; Application of elastic follow-up model to welded joints

kasahara, Naoto

PNC TN9410 95-213, 38 Pages, 1995/08

PNC-TN9410-95-213.pdf:1.72MB

In order to evaluate thermal transient strength of welded components in nuclear plants, conventional structural design codes provide conservative strength reduction factors, which are desired to be rationalized. Author extended the generalized clastic follow-up model to evaluate main causes of strength reduction of welded joints. As main causes of strength reduction of welded joints subjected to cyclic thermal transients, attention was given to (1)Metallurgical discontinuity in which the different deformation response between base metal and weld metal can result in nonuniform stresses and strain across the weldment, (2)Structural discontinuity at penetration beads of welded joints, and (3)Degradation of Weld Metal. In order to evaluate (1) and (2) of above factors, an elastic follow-up model was successfully applied. Thermal transient strength test results provide further substantiation of the validity of the elastic follow-up model for ensuring adequate life in elevated temperature component weldments. Author applied the creep-fatigue life prediction methods based on the elastic follow-up model to evaluate test results of a welded vessel model. Proposed method was proved to be adequate through comparison of predicted damagc with observed cracks data.

Studies on the porosity in welding joints, 3rd report; Results of experimental welding

; ; Ando, Yoshio*

Yosetsu Gakkai-Shi, 31(12), p.980 - 985, 1962/00

http://ci.nii.ac.jp/naid/110003402345

no abstracts in English

Corrosion behavior of weld joint of carbon steel overpack under geological environment, 2; Corrosion behavior of engineering scale testing

Yamazaki, Kazutoshi*; Takao, Hajime*; Kikuchi, Takahiro*; Kuriki, Yoshiro*; Kobayashi, Masato*; Kawakubo, Masahiro*; Shirase, Mitsuyasu*; Iwata, Yumiko*; Tochigi, Yoshikatsu*; Nakayama, Gen*; et al.

no journal, , 

Among factors affecting the corrosion behavior of carbon steel overpack, in order to consider materials (size) and realistic environmental factors which are difficult to reproduce in the laboratory scale test, engineering scale tests in the underground environment were carried out. A mock-up test of the same scale was also carried out on the ground with the aim of controlling and evaluating factors that govern the corrosion phenomenon. As a result of the test for about 3 years, there was no big difference between the average corrosion amount and the maximum corrosion amount of the simulated overpack base metal and the welded part. On the other hand, unlike the laboratory scale test, localization of corrosion due to the adhesion between the buffer material and the simulated overpack was also confirmed during the initial transient period.