Tribological behaviour of microalloyed and conventional C–Mn rail steels in a pure sliding condition

This paper compares the tribological behaviour of microalloyed rail steel with conventional C–Mn rail steel under different test conditions (load, temperature and humidity). Pin-on-disc tribological tests were performed inside a climate chamber under different loads (20, 30 and 40 N), relative humidity (15, 55 and 70%) and temperatures (20 and 40 ℃). After the friction and wear tests, the worn surfaces were analysed using both confocal and scanning electron microscopies. The results obtained show that the use of microalloyed steel in railway applications under severe conditions (high loads and humidity) could lead to increased service life of the rails and could extend the time between maintenance operations

Influence of Different Application of Lubricants on Wear and Pre-existing Rolling Contact Fatigue Cracks of Rail Materials

Rolling contact fatigue (RCF) of rail can be a significant problem affecting safety and maintenance. Rail materials have been optimized to reduce it, but not enough is known about how friction management products applied to the rail affect crack growth. This study presents experimental results carried out to explore the influence of different lubricants and application orders on wear and pre-existing RCF cracks in rail materials. The results indicate that the types or properties of lubricants have a vital role in the wear rate and fatigue crack growth characteristics of rail materials after conditioning with 5000 dry cycles to initiate cracks. Using a different application order of two lubricants has a significant influence on the crack growth angles in the rail rollers

A review of friction models in interacting joints for durability design.

This paper presents a comprehensive review of friction modelling to provide an understanding of design for durability within interacting systems. Friction is a complex phenomenon and occurs at the interface of two components in relative motion. Over the last several decades, the effects of friction and its modelling techniques have been of significant interests in terms of industrial applications. There is however a need to develop a unified mathematical model for friction to inform design for durability within the context of varying operational conditions. Classical dynamic mechanisms model for the design of control systems has not incorporated friction phenomena due to non-linearity behaviour. Therefore, the tribological performance concurrently with the joint dynamics of a manipulator joint applied in hazardous environments needs to be fully analysed. Previously the dynamics and impact models used in mechanical joints with clearance have also been examined. The inclusion of reliability and durability during the design phase is very important for manipulators which are deployed in harsh environmental and operational conditions. The revolute joint is susceptible to failures such as in heavy manipulators these revolute joints can be represented by lubricated conformal sliding surfaces. The presence of pollutants such as debris and corrosive constituents has the potential to alter the contacting surfaces, would in turn affect the performance of revolute joints, and puts both reliability and durability of the systems at greater risks of failure. Key literature is identified and a review on the latest developments of the science of friction modelling is presented here. This review is based on a large volume of knowledge. Gaps in the relevant field have been identified to capitalise on for future developments. Therefore, this review will bring significant benefits to researchers, academics and industrial professionals