Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Hiroyoshi Tanaka Last modified date:2018.06.11

Assistant Professor / Machine Design and Bionic Systems / Department of Mechanical Engineering / Faculty of Engineering

1. 田中 宏昌, Permeation of hydrogen into steel under rolling contact in various gas with additive free oils, Tribology frontier 2016, 2016.11, This study describes effects of additives on hydrogen permeation into bearing steel under rolling contact. Rolling contact tests were conducted under oil lubrication in hydrogen. PAO, POE, PPG were used as lubricants..
2. 田中 宏昌, Effects of lubricant additives on hydrogen permeation under rolling contact, Tribology frontier 2015, 2015.10, This study describes effects of additives on hydrogen permeation into bearing steel under rolling contact. Rolling contact tests were conducted under oil lubrication in hydrogen. WS2 nanoparticles, TOP, DBDS, ZDDP and MoDTC were used as lubricant additive.
3. 田中 宏昌, Hydrogen Permeation through Oxide Layer on Steels, ITC2015, 2015.09, This paper describes the surface film formation and hydrogen permeation on steel surface under hydrogen environment. Sliding tests of bearing steel AISI52100 and stainless steel AISI440C are conducted in hydrogen and vacuum with oil lubrication..
4. 田中 宏昌, Joichi Sugimura, Suguru Ikeda, Different failure modes in rolling contact of steel under grease lubrication, STLE tribology frontier 2014, 2014.10, Rolling contact fatigue test under grease lubrication is conducted for the purpose of clarifying effect of surrounding gas on rolling contact fatigue life. The influence of temperature, atmosphere, and grease types is investigated through surface analysis, hydrogen diffused in steel, the composition of surface film and the characteristics of lubrication state. The bearing life depended on environment and lubricant, and surface failure was classified into three types in terms of surface roughness and temperature change. At higher temperature, there is a tendency that roughness becomes smaller and bearing life is extended..
5. 田中 宏昌, Joichi Sugimura, Taiki komatsu, Effects of environmental gas on decomposition of lubricant and hydrogen generation at nascent iron surface, Asiatrib2014, 2014.02, Lubricated sliding tests of iron were made in a temperature controlled chamber, and the amount of hydrogen generated was determined with gas chromatography. The lubricants used included polyalphaolephine polyorester, polypropyrenglycol and dimethyl silicone oil. It was found that the amount of hydrogen generated is significantly larger when nascent surface is continuously created than under static non-sliding conditions. It was also found that hydrogen generation is retarded when the environment gas contains more oxygen. Among the oils tested, the silicone oil showed very low hydrogen generation under non-sliding condition while it generates much greater amount of hydrogen than other lubricants..
6. 田中 宏昌, EFFECTS OF HYDROGEN ON STRUCTURAL CHANGE AND ROLLING CONTACT FATIGUE OF STEEL, Asiatrib2014, 2014.02, This paper describes experimental study of rolling contact fatigue under various conditions. Ball-on-disk type rolling contact fatigue tests were conducted in hydrogen and other gasses. Some of the specimens contained extra amount of hydrogen by the pre-treatment of hydrogen exposure prior to the tests. After the rolling contact fatigue test, hydrogen content measurement with thermal desorption spectroscopy, cross section observations with SEM(Scanning electron microscope) and EsB (Energy selective back-scatter) detector were conducted..
7. 田中 宏昌, Rolling contact fatigue test with greases in hydrogen environment, WTC2013, 2013.09, This paper describes a study on grease lubrication of rolling element bearing under hydrogen environment. Rolling contact fatigue tests were conducted with greases under hydrogen and other gas environments. In order to find influences of hydrogen on several greases, relationship between RCF life and permeation of hydrogen and/or surface condition are focused on..
8. 田中 宏昌, PERMEATION OF HYDROGEN INTO STEEL IN SIMPLE CYCLIC CONTACT TESTS, ISFF7, 2013.04, This paper describes permeation of hydrogen under simple mechanical motion at tribo-interface. It has been believed that hydrogen plays an important role in degrading mechanical properties of ferrous materials in rolling contact. It is necessary to study each of the effects of elementary processes at contact and slip on hydrogen permeation into steel. An experimental apparatus was used which enabled a variety of simple contact tests with cyclic normal loading and reciprocating sliding for each in controlled environment.
9. Hiroyoshi Tanaka, Rolling Contact Fatigue under Grease Lubrication in Hydrogen, IJTC2012, 2012.10, In order to investigate the effects of greases on rolling contact fatigue life in hydrogen, we will focus on how surface film formation
Wettability or polarity of base oil, thickener of grease affects the surface initiated and/or subsurface initiated rolling contact fatigue.
10. Rolling fatigue in hydrogen gas environment.
11. Sliding friction and wear of DLC coating films in hydrogen environment.
12. Sliding experiments in hydrogen and surface analysis of DLC coating films.