The friction and wear behaviors of a Fe-19Cr-15Mn-0.66N high nitrogen
austenitic stainless steel (HNSS) were investigated. Tribological
investigations were carried out under different applied loads of 5 N, 10 N,
15 N and 20 N. Scanning electron microscope (SEM) and laser scanning
confocal microscope (LSCM) were used to understand the wear mechanisms under
different loads and the reasons for the improved wear resistance. The lower
friction coefficient and improved wear resistance were observed with the
increase in applied loads. Under a higher load, the friction enhanced the
work hardening ability of HNSS, which in turn improved its surface hardness and
thus the increased wear resistance of HNSS.
The friction and wear behaviors of Fe-19Cr-15Mn-0.66N steel were investigated under applied loads of 5 N and 15 N at the wear-testing temperatures of 300 °C and 500 °C using a ball-on-disc tribometer. The wear tracks were evaluated by scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) to reveal the variation in morphologies. Energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were used to determine the components of oxide layers formed on wear surfaces. The results demonstrated that the oxide layers are favorable for obtaining a low friction coefficient under all conditions. The average friction coefficient decreased with increasing load at 300 °C, while it increased with the increase in applied load at 500 °C. At 300 °C, severe abrasive wear characterized by grooves resulted in a high friction coefficient with 5 N applied, whereas the formation of a denser oxide layer consisting of Cr2O3, FeCr2O4, Fe2O3, etc., and the increased hardness caused by work hardening led to a decrease in friction characterized by mild adhesive wear. At 500 °C, the transformation of Fe2O3 to the relatively softer Fe3O4 and the high production of lubricating Mn2O3 resulted in a minimum average friction coefficient (0.34) when 5 N was applied. However, the softening caused by high temperature weakened the hardening effect, and thus the friction coefficient increased with 15 N applied at 500 °C.
Stick–slip behavior between friction pairs causes
severe
vibration problems such as abrasion and noise pollution, leading to
material loss and deterioration in human health. This phenomenon is
extremely complex because the surfaces of friction pairs have various
asperities with different sizes. Therefore, it is of importance to
understand the scale effect of asperities on the stick–slip
behavior. Here, we selected four kinds of zinc-coated steels with
multiscale surface asperities as a presentative example to reveal
what types of asperities play the key role in affecting the stick–slip
behavior. It is discovered that the stick–slip behavior is
dominated by the density of small-scale asperities rather than large-scale
asperities. High-density small-scale asperity increases the potential
energy between asperities of the friction pairs, which leads to stick–slip
behavior. It is suggested that decreasing the density of small-scale
asperity on the surface significantly suppresses the stick–slip
behavior. The present study reveals the scale effect of surface asperities
on the stick–slip behavior and thus could offer a pathway to
tailoring the surface topography of a wide range of materials for
suppressing the stick–slip behavior.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.