All issues
Volume 43 (2005)
- Issue 6 Pages 320-
- Issue 5 Pages 254-
- Issue 4 Pages 190-
- Issue 3 Pages 130-
- Issue 2 Pages 64-
- Issue 1 Pages 4-
Predecessor
Volume 43, Issue 5
Displaying 1-5 of 5 articles from this issue
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Original Paper
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Waichi IWASAKI2005 Volume 43 Issue 5 Pages 254-261
Published: 2005
Released on J-STAGE: November 10, 2005
JOURNAL FREE ACCESSFuel cell has a important roll to spread hydrogen energy. In order to realize the Polymer Electrolyte Fuel Cell (PEFC) , 30kW PEFC power plant was prototyped, and evaluated the power generation efficiency. For purpose of increasing operation temperature, we developed high-temperature polymer membranes, and obtained successful result of 400hr test run in 120°C, 5kW Solid Oxide Fuel Cell (SOFC) was manufactured by way of trial, and obtained the data of power density (W⁄cm2) that was compared with another data. Recently the power density achieved about 1 (W⁄cm2) contributing to increase the power generation efficiency, we evaluated the relation of equipment construction cost to the power density. We proposed high efficient power plant system that has a competitive edge over existing state of art thermal power plant. A material development for SOFC has also considered in this paper.View full abstractDownload PDF (587K) -
Satoshi NAGATA, Toshiyuki SAWA, Hirokazu TSUJI, Wataru MAEZAKI2005 Volume 43 Issue 5 Pages 262-270
Published: 2005
Released on J-STAGE: November 10, 2005
JOURNAL FREE ACCESSFinite Element analysis on a bolted flange connection with a cover of pressure vessel (CPV) , in which a spiral wound gasket was inserted, under internal pressure was performed by taking hysteresis of the gasket into account. Leakage on an actual bolted flange connection with a CPV a spiral wound gasket inserted was also measured and its leak tightness was obtained by the experimental tests. Using the calculated contact gasket stress distribution in the bolted flange connection with the CPV under internal pressure and the measured tightness parameter, the values of new gasket constants were obtained by taking account the contact gasket stress reduced by internal pressure. The difference in the new gasket constants between the estimated values obtained from the actual bolted flange connection with the CPV and those obtained by the procedure specified by the PVRC was small. In addition, a method was demonstrated that determines the required bolt preload to achieve the required tightness parameter under internal pressure. The obtained results of the bolt preload for the bolted flange connection with the CPV were in a fairly good agreement with those obtained by the PVRC procedure under a lower pressure application. In PVRC procedure, 1. 5 times of the required tightness parameter in pressurized condition is used to determine the bolt preload. However, it was shown that the factor 1. 5 used in PVRC procedure was insufficient under a higher pressure application.View full abstractDownload PDF (239K) -
Katsuyoshi MORIKAWA, Gosaku KAWAI, Yoshio OUE, Hideaki NAKAYAMA2005 Volume 43 Issue 5 Pages 271-277
Published: 2005
Released on J-STAGE: November 10, 2005
JOURNAL FREE ACCESSThree types of friction welded joint of C4641 naval brasS and S25C carbon steel were produced under thee kinds of friction pressure welding conditions with different upset pressures. In the friction interface, the organization of the naval brass was fine grained. It was confirmed that the friction heat affected one part. Tensile strength was 47%, 57%, 70% of the naval brass base metal tensile strength in proportion to the upset pressure, when these joints tensile tests were performed. The upset pressure seemed to affect the tensile strength. This study conducted fatigue tesK on a friction welded joint of high tensile strength to examine pressure welding conditions and their relation to fatigue strength. The fatigue strength of the joint exhibited a value similar to the S25C base meta1. The near interface was the rupture position from the fracture surface tensile test and fatigue test observations. The part with the weak joint was located on thc naval brass side, which is similar to the friction surface.View full abstractDownload PDF (468K) -
Report 2 Embrittlement behavior of the interface between base metal and stainless steel overlay weld.Rinzo KAYANO, Hiroaki MORI, Tetsuro AGO, Kazutoshi NISHIMOTO2005 Volume 43 Issue 5 Pages 278-285
Published: 2005
Released on J-STAGE: November 10, 2005
JOURNAL FREE ACCESSIn petroleum pressure vessels, some thermal degradation problems occurred in the post weld heat treatment (PWHT) such as the sigma phase transformation in the overlay weld of austenitic stainless steel and the carbide precipitation at the interface between the base metal of 2. 25Cr-1Mo steel and the overlay weld. In addition, hydrogen embrittlement occurred at operating conditions, such as elevated temperature and high pressure hydrogen environment. In this study, the degree of thermal and hydrogen embrittlement in the pressure vessel steel was evaluated by the notch tensile test. The tensile strength and rupture ductility decreased by increasing of the tempering parameter in PWHT and severer hydrogen exposure conditions. The sigma phase transformation in the overlay welds after PWHT was verified by optical microscopic observation of cross section for the tensile tested specimen. The carbide precipitation at the interface and hydrogen embrittlement was verified by the micro structure and fractographic observation of the specimen. It was confirmed that the crack propagated through the austenite grain boundary in the overlay weld near the carbide layer at the interface due to hydrogen embrittlement.View full abstractDownload PDF (755K)
Lecture
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-Creep Rupture, Excessive Deformation due to Creep and Creep Ratcheting-Takuya SATO2005 Volume 43 Issue 5 Pages 286-293
Published: 2005
Released on J-STAGE: November 10, 2005
JOURNAL FREE ACCESSDownload PDF (348K)
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