Entity

Time filter

Source Type

Kawasaki, Japan

Isomoto Y.,Hiroshima University | Kawanishi T.,Hiroshima University | Kawahara Y.,Dai - ichi High Frequency
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals | Year: 2013

Self-fluxing alloys are useful for component materials as coatings in energy conservation systems and power plants due to high resistance of high temperature corrosion and erosion. However, the mechanical properties of the self-fluxing alloy coatings at high temperatures have not been precisely investigated. In order to develop highly durable coatings and apply to practical services, we focused on measurements of hardness and fracture toughness for the self-fluxing alloys at room and high temperatures. Spherical particle impact tests were conducted for three types of self-fluxing alloys to obtain dynamic hardness and dynamic fracture toughness. Three point bending tests were additionally performed. As results, the hardness and fracture toughness of the three self-fluxing alloys were found to be almost constant at room and high temperatures up to 873 K, although a little decrease in fracture toughness occurred at 1073 K. The fracture toughness related to elastic modulus and F/C1-5 (F: load, C: crack length), and have a tendency of increasing with increase in Brinell hardness. © 2013 The Japan Institute of Metals and Materials. Source


Isomoto Y.,Hiroshima University | Kawanishi T.,Hiroshima University | Kawahara Y.,Dai - ichi High Frequency | Yoshihara M.,Yokohama National University
Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals | Year: 2013

Self-fluxing alloy coatings are useful for components of industrial equipments in sand erosion or wear environments as well as high temperature corrosive and oxidation environments. However, the erosion characteristics by solid particle for the self-fluxing alloys have not been adequately investigated, then needed in order to develop highly durable coating alloys and apply to practical erosive services. Erosion tests at room temperature were conducted for three types of self-fluxing alloys to obtain impact angle dependence of erosion rate or normalized erosion using a sand blast type erosion test rig. We focused on hardness, fracture toughness and fracture energy of self-fluxing alloys at room and high temperatures. The relationships between erosion characteristics and these mechanical properties were discussed and erosion rate of the self-fluxing alloys at high temperature was extrapolated. The exponent numbers which show impact angle dependence of sand erosion, and erosion rates at an impact angle of 90 degrees were well related to micro Vickers hardness and roughly related both to Brinell hardness and to fracture energy. It was found that the erosion rates for the self-fluxing alloys at high temperatures up to 873 K could be estimated as almost equal to that at room temperature, as well as equivalent mechanical properties at temperatures up to 873 K. © 2013 The Japan Institute of Metals and Materials. Source


Kawahara Y.,Dai - ichi High Frequency
Oxidation of Metals | Year: 2016

Localized corrosion (LC) sometimes appears in boiler tubes exposed in severely corrosive combustion gases including Cl, S and O, but prediction and on-site maintenance of LC is actually difficult in many cases. Therefore understanding the cause of LC is considered to be important to maintain safety services and estimate lifetime in high temperature facilities. This LC occurs due to formation of partially different corrosive conditions due to fuels, condition of combustion, designing of boilers, and materials. In this paper, investigation results of macroscopic LC and influenced factors formed in actual boilers were described with the four cases of fossil fuel, biomass and WTE boilers, and also described against any coatings. Mechanisms of each LC were considered individually by using cut-off samples of damaged tubes, detailed analyses of corrosive environments and results of laboratory tests. From these considerations, protective oxide layers and not only static factors but also dynamic factors arising in operated conditions such as temperature and composition fluctuations were concluded to be important for the accurate lifetime evaluations of tube materials and coatings. © 2015, Springer Science+Business Media New York. Source


Masuta H.,Kanagawa University | Watanabe H.,Kanagawa University | Sato K.,Dai - ichi High Frequency | Lim H.-O.,Kanagawa University
2013 10th International Conference on Ubiquitous Robots and Ambient Intelligence, URAI 2013 | Year: 2013

This paper describes a pipe inspection robot with multiple joints. We are developing the pipe inspection robot which is able to move in vertical pipe and correspond with changing radius pipe. Furthermore, our robot can go around a branch pipe by attaching to 2 robots. On the other hand, it is difficult to recognize a position of branch pipe, self position and self posture because inside of pipe is dark and surrounded by walls. In this paper, we develop the fiber grating vision sensor to recognize a position of branch pipe for the pipe inspection robot. We propose the branch pipe recognition using fiber grating vision sensor. And we show several experimental results of branch pipe recognition. © 2013 IEEE. Source


Trademark
Dai - ichi High Frequency | Date: 2014-09-05

drying apparatus; recuperators; steamers; evaporators; distillation apparatus; heat exchangers; industrial furnaces; boilers; boilers for industrial plants; boiler tubes for boilers; boiler tube panels for boilers.

Discover hidden collaborations