Vol.8 No.2 2015

Research paper : Development of material testing equipment in high pressure gaseous hydrogen and international collaborative work of a testing method for a hydrogen society (T. IIJIMA et al.)−68−Synthesiology - English edition Vol.8 No.2 (2015) AuthorsTakashi IIJIMACompleted the doctorate courses at the Department of Metallurgy, Materials Science and Materials Processing, Graduate School of Engineering, Tohoku University in 1988. Doctor of Engineering. Joined the Tohoku National Industrial Research Institute, Agency of Industrial Science and Technology in 1993. Visiting researcher at the Max Plank Institut für Metallforschung in 1997-1998. After reorganization to AIST in 2001, worked at the Smart Structure Research Center, Research Institute of Instrumental Frontier, and Research Center for Hydrogen Industrial Use and Storage. Group Leader, Hydrogen Industrial Use and Storage Group, Energy Technology Research Institute, AIST from 2013. Visiting Professor, Tokyo University of Science (Collaborative Graduate School) and Visiting Professor, Kyushu University. In this paper, was in charge of organizing the data and writing up the paper.Takayuki ABEEngaged in the research of metal fatigue fracture at the National Research Institute for Metals (NRIM) (currently National Institute for Materials Science (NIMS)) from 1970 to 2009. Obtained Doctor of Engineering at the Shibaura Institute of Technology in 2004. Joined the Hydrogen Industrial Use and Storage Group, Energy Technology Research Institute, AIST in 2011. Engaged in fracture toughness tests in high-pressure gaseous hydrogen environment at the Hydrogen Industrial Use and Storage Group, Energy Technology Research Institute, AIST from 2013. In this paper, was in charge of the consideration of conditions for fracture toughness tests and the execution of the tests.Hisatake ITOGACompleted the doctorate courses at the Mechanical and Civil Engineering Division, Graduate School of Engineering, Gifu University in 2005. Doctor of Engineering. Faculty member, Nakanihon Automotive College from 1995 to 2007. Research Fellow, Research Center for Hydrogen Industrial Use and Storage, AIST from 2007 to 2013. Associate Professor, Research Center for Hydrogen Industrial Use and Storage, Kyushu University from 2013. Engaged in the research for strength property of metallic materials, and particularly after 2007, engages in the research on effect of hydrogen on the material strength property. In this paper, was in charge of the analysis of fracture toughness test results.Discussions with Reviewers1 OverallQuestion & Comment (Mamoru Nakamura, AIST)The establishment of a material evaluation system to guarantee the reliability of metallic materials that can be used in high-pressure hydrogen conditions and the establishment of its international standard are essential for the construction of hydrogen storage and a supply system to enable practical use of FCVs. This paper is very interesting as it describes the results of joint research with an American national institute for an evaluation method of the material properties, particularly, fracture toughness.Question & Comment (Hiroaki Hatori, AIST)The history of development of the material evaluation method for high-pressure hydrogen storage vessels that are essential for realizing FCVs is interesting in terms of synthesiology, and this is a technological development field that is clearly related to society. The international standardization strategy that is currently in progress will be a key to the further diffusion of FCVs, and I think there is great significance in conducting a synthesiological consideration with an eye on future efforts.2 Current situation of the research pertaining to standardization in Japan and overseas, and organization of the descriptions of international standardization strategiesQuestion & Comment (Mamoru Nakamura)The international standardization of the evaluation method for fracture toughness of metallic materials that can be used under hydrogen pressure is still in the phase of comparing three methods, and there is no indication of the direction or strategy for standardization. It will be easier for readers of this paper to understand, if you first describe the overall picture and the current situation of property evaluation under hydrogen pressure in Japan and overseas, then explain the positioning of fracture toughness that is discussed here, and then describe the result of the international joint research.Specifically, the relationships among some of the ASME standards described in “2.2 Use standard of the materials used in high-pressure gaseous hydrogen equipment” and “4.1 Consideration of the fracture toughness evaluation method for finite life design,” the Japanese standard (is it in a preparatory stage?), and the international standard are unclear. I think you should organize and describe them carefully.Answer (Takashi Iijima)For the standardization in Japan, USA, and Europe, I organized the situations of the FCV on-board vessel and the hydrogen filling station vessel in chapter 2, and described the strategy for contributing toward the international standardization of material testing methods. The situation of testing equipment for high-pressure gaseous hydrogen condition in the world was overviewed in chapter 3, and we explained our efforts in developing the equipment. Also, for fracture toughness value, as mentioned in chapter 2, various evaluation methods are being suggested and searched. We described the result of international joint research with the Sandia National Laboratories for the fracture toughness evaluation method by the constant displacement method and the rising displacement method in chapter 4.Question & Comment (Hiroaki Hatori)Comment 1: For chapter 3, I think it is necessary to strengthen the synthetic consideration of the process (scenario, hypothesis) to realize the research goal for the material evaluation method that you succeeded in developing, as well as the selection and integration of the elemental technologies. Along with the efforts toward future international standardization in chapter 4, I think the readers will understand better if you add a figure that summarizes the scenario and strategy of R&D as a model. For the details of technology in chapter 4, the explanation should be simplified and some parts should be left to the reference material,


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