Analytical study on the growth and transfer of adhesive substances generated on the surface in the early stage of sliding

This study is intended to produce reliable quantitative information about adhesive wear phenomena of metallic materials in the early stage of dry sliding. The outcome of this study will contribute to the refinement of the physical model of a wear mechanism. A devised technical method was employed in the study to enable data acquisition linked with the position of measurement on the specimen and objective combinational analyses of plural kinds of tribological data. Quantitative analyses on the relationship between friction force and specimen displacement perpendicular to the sliding surface was carried out. Data analyses on the self-mated dry sliding of austenitic stainless steel clarified the existence of several elemental processes of adhesive mechanism with quantitative parameters such as the growth rate and the size of adhesive substances generated at the interface between sliding members. The influences of the relative humidity (RH) in an atmospheric air on the numerical parameters were revealed as well and they were interpreted into the physical model of the adhesive wear mechanism

Quantitative Estimation of Adsorbed Water Layer on Austenitic Stainless Steel

A study was carried out to estimate the thickness of the adsorbed water layer on the surface of austenitic stainless steel (JIS SUS316) in different atmospheric humidity conditions. The purpose of the study is to have a quantitative data on water adsorption that has influences on the tribological phenomena. The mass of stainless steel plate was determined by the weighting method as a function of the relative humidity (RH) in ambient atmospheric air. An experimental device consisting of atmospheric humidity controller and high sensitivity analytical balance with affixed airtight chamber was used for the purpose of the study. The result of water adsorption progression on SUS316 surface has been discussed and schematically demonstrated. It is clarified that the thickness of adsorbed water is significantly large to influence the tribological properties as demonstrated in a schematic model of the interface state of pin-on-disk prior to contact in high RH

Analysis on the Mechanism of Humidity to Influence the Very Early Stage of Sliding under Different Load

A study was carried out on the influences of atmospheric humidity in the very early stage of sliding for austenitic stainless steel (JIS SUS316). Pin-on-disk tests were conducted under different rates of relative humidity (RH). A relatively low magnitude of applied load to lessen the influences of mechanical effect was employed for emphasizing the humidity effect on tribological phenomena. The results of the current study were compared with our previous study results obtained at higher magnitude of applied load. The comparison suggested different mechanisms of adsorbed water layer exert influences on the tribological phenomena in the very early stage of the sliding when applied load was changed

Influences of surface roughness on the water adsorption on austenitic stainless steel

Presence of adsorbed water on the solid surface gives significant influences on the tribological phenomena. This study aims to elucidate how the difference in surface roughness of austenitic stainless steel influences the amount of adsorbed water. Firstly, the necessary time for the adsorbed water to saturate on the surfaces with different roughness when relative humidity (RH) changed was determined by weighing method. Then, the saturated adsorbed water amount at different RH % was determined for the surfaces with different roughness. It was clarified that the rougher surfaces tend to require longer time for water adsorption to achieve the saturation level and adsorb more amount of water compared with smoother surfaces