*RYOTA KOBAYASHI¹, KOJI HASEGAWA¹, NAOSHI ISHIHARA¹, YOSHITAKA KUBOTA² (1. FINE SINTER CO.,LTD.(Japan), 2. RAILWAY TECHNICAL RESEARCH INSTITUTE(Japan))

*Hiroki TANAKA¹, Masaki OTSUBO¹, Hiroto SHIMOMURA¹, Takayuki TAKASUGI², Yasuyuki KANENO² (1. Machinery Parts Business Department, Nippon Tungsten Co.,Ltd.(Japan), 2. Graduate School of Engineering, Osaka Prefecture University(Japan))

*Hiroshi FUJIWARA¹, Koki SONE¹, Fuminori UEGUCHI², Hiroyuki MIYAMOTO² (1. Shizuoka Institute of Science and Technology(Japan), 2. Doshisha University(Japan))

*WEIWEI ZHOU¹, Keiko KIKUCHI ¹, Naoyuki NOMURA ¹, Akira KAWASAKI¹ (1. Tohoku University(Japan))

*Tran Duc HUY¹, Do Thanh BINH², Hiroyuki MIYAMOTO³ (1. School of Materials Science and Engineering, Hanoi University of Science and Technology, Vietnam(Viet Nam), 2. Faculty of Metallurgy, College of Mechanics and Metallurgy, Thai Nguyen City, Thai Nguyen, Vietnam(Viet Nam), 3. Department of Mechanical and Systems Engineering, Doshisha University, Japan(Japan))

*Makoto KOBASHI¹, Naoki TAKATA¹, Asuka SUZUKI¹ (1. Graduate School of Engineering, Nagoya University(Japan))