The Experts below are selected from a list of 5325 Experts worldwide ranked by ideXlab platform
P E J Riveradiazdelcastillo - One of the best experts on this subject based on the ideXlab platform.
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the relationship between 100cr6 steelmaking inclusion microstructure and Rolling Contact Fatigue performance
International Journal of Fatigue, 2019Co-Authors: Jakub Jelita Rydel, Adam M Gola, Ke Geng, Chenghan Lau, Haiwen Luo, P E J RiveradiazdelcastilloAbstract:Abstract A processing-microstructure-performance approach is followed to study three bearing steel samples manufactured from the most frequently used continuous casting routes. The inclusion microstructures of the samples were altered by varying the metallurgy and hot working conditions. Inclusion size distribution information is obtained, showing the steel-making route that results in the highest cleanliness. 3D analysis of inclusion morphologies using electrolytic extraction indicates the irregularities on the surface to be favourable sites for crack nucleation under RCF. Flat-washer and ball-on-rod tests were conducted to study the Rolling Contact Fatigue life of the steels, with the results from the flat-washer testing method being more representative for bearing life. This research suggests that early Fatigue of bearings is governed by silicate fragmentation and late Fatigue by TiN inclusions.
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strain induced martensite decay in bearing steels under Rolling Contact Fatigue modelling and atomic scale characterisation
Acta Materialia, 2017Co-Authors: Wenwen Song, E I Galindonava, P E J RiveradiazdelcastilloAbstract:Martensite decay in bearing steels manifested as dark etching regions (DERs) under Rolling Contact Fatigue (RCF) is modelled. The proposed model is established based on a dislocation-assisted carbon migration mechanism. The proposed model is capable of predicting the progress of DER formation and the corresponding mechanical property evolution with increasing number of cycles, in good agreement with the experimental data reported throughout seventy years. The effects of RCF testing conditions on DER formation are studied and a useful tool, DER% maps, is developed for illustrating the temperature, Contact pressure and number of cycles for DER occurrence. Moreover, an atom probe tomography study is carried out, revealing the nature of DER ferrite and obtaining strong evidence supporting the postulated DER formation mechanism. The successful application of the dislocation assisted carbon migration mechanism to DER formation provides a plausible explanation to the phenomenon of martensite decay under Rolling Contact Fatigue.
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Rolling Contact Fatigue in martensitic 100cr6 subsurface hardening and crack formation
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Jeehyun Kang, R H Vegter, P E J RiveradiazdelcastilloAbstract:Rolling Contact Fatigue tests on 100Cr6 steel were carried out with a ball-on-rod tester. Microstructural damage was manifested by gradual hardness changes under the subsurface, and microcracks formed adjacent to inclusions; both being evidence of plastic deformation. The hardness increase appears to be due to the development of residual stress, while the microcracks form as a result of the concentration of stress around inclusions. The microcrack orientation is suggested to be affected by the stress state, depending on the degree of residual stresses generated. The residual stress development may be a key factor for optimising the bearing element testing methods, by considering its influence on the damage morphology.
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Rolling Contact Fatigue in bearings multiscale overview
Materials Science and Technology, 2012Co-Authors: Jeehyun Kang, B Hosseinkhani, P E J RiveradiazdelcastilloAbstract:AbstractFor over a century, Rolling Contact Fatigue in bearings has been recognised as a key feature limiting bearing life. The phenomenon is manifested through dark etching regions, 30 and 80° white etching bands as well as white etching areas, the latter often forming intricate defects commonly referred to as butterflies. Their presence depends on testing conditions, such as Contact pressure, temperature, number of revolutions and steel cleanliness. Microstructural inspection demonstrates that precipitate shearing, dissolution, cell and nanocrystal formation as well as matrix/inclusion debonding may take place throughout bearing life. Such microstructural features have a negative effect on bearing hardness, strength, ductility and toughness, usually preceding failure. The present review shows how such phenomena are interconnected, highlighting the need for integral characterisation and modelling across the scales. This will aid in the conception of new heat treatments, steel grades and microstructures f...
Piao Zhongyu - One of the best experts on this subject based on the ideXlab platform.
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Rolling Contact Fatigue behavior of thermal sprayed coating a review
Critical Reviews in Solid State and Materials Sciences, 2019Co-Authors: Piao Zhongyu, Wang Haidou, Xu Binshi, Yu XiaoxiaoAbstract:Rolling Contact Fatigue (RCF) of sprayed coating is complicated process relating to materials, structures, loading conditions, etc. Herein, the research works over the past decades in RCF of spraye...
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investigation of Rolling Contact Fatigue damage process of the coating by acoustics emission and vibration signals
Tribology International, 2012Co-Authors: Zhang Zhiqiang, Li Guolu, Wang Haidou, Xu Binshi, Piao Zhongyu, Zhu LinaAbstract:Abstract The objective of present study is to investigate Rolling Contact Fatigue (RCF) damage process of the sprayed coating by acoustics emission (AE) and vibration signals. Fe-based alloy coating was prepared on 1045 steel using the plasma spraying technology. The results show that RCF damage process is composed of four stages. The AE with higher sensitivity can detect Fatigue damage details, such as the material deformation, crack initiation and growth. While the vibration can only reflect the final failure, such as extensive and deeper pittings. The analysis of AE waveform and frequency are effective methods for studying RCF damage process.
Leon M Keer - One of the best experts on this subject based on the ideXlab platform.
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parametric study on stressed volume and its application to the quantification of Rolling Contact Fatigue performance of heterogeneous material
Tribology International, 2017Co-Authors: Wanyou Yang, Yanyan Huang, Qinghua Zhou, Jiaxu Wang, Xiaoqing Jin, Leon M KeerAbstract:Abstract This research explores the influence of distributed inhomogeneities and surface asperities on the stressed volume of heterogeneous material in Contact with a sphere. The recently developed modeling method for solving rough-surface Contact problems involving distributed inhomogeneities, incorporated with FFT algorithms and a mesh differential refinement scheme, is utilized. The effective stressed volume, quantitatively described by effective depth, length and width, is investigated to characterize the Rolling-Contact-Fatigue influence zone in heterogeneous material. Furthermore, a parametric study is conducted for the influences of inhomogeneity distribution and surface roughness on volumetric stress integral in order to understand the Rolling Contact Fatigue performance of particle-laden inhomogeneous materials.
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an analysis of the effect of hard coatings on near surface Rolling Contact Fatigue initiation induced by surface roughness
Wear, 1997Co-Authors: I A Polonsky, T P Chang, Leon M Keer, William D. SproulAbstract:Abstract The effect of hard coatings on the Fatigue life of Rolling elements subject to cyclic concentrated Contact loading (such as bearing races or gears) is studied theoretically. Approximate analytical formulae are derived that can be used to estimate the coating thickness required to protect the substrate effectively from the small-scale Contact stress spikes produced by surface roughness, and thus prevent near-surface Rolling Contact Fatigue initiation. The present model, although crude, takes into account the multiscale nature of real surface roughness, as well as interaction between different roughness components. The relative danger of near-surface Fatigue initiation and the potential effect of a hard coating are determined by the interplay between the coating thickness, the typical size of defect responsible for Fatigue crack initiation and the power spectrum of surface roughness. The model predictions agree qualitatively with the results of a companion experimental study. The analysis indicates that in order to be truly effective against Rolling Contact Fatigue, a hard coating has to be relatively thick (say, ≥3 μm), adherent, and have the fine microstructure and the associated resistance to cohesive failure under cyclic Contact loading currently found in thin PVD TiN coatings.
Anders Ekberg - One of the best experts on this subject based on the ideXlab platform.
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Rolling Contact Fatigue wear and broken rail derailments
Wear, 2016Co-Authors: Eric Magel, Anders Ekberg, Peter Mutton, Ajay KapoorAbstract:Rolling Contact Fatigue (RCF) and wear are inevitable in the wheel/rail system, but resulting failures and derailments need not also be inevitable. Understanding why and under which conditions broken rails and derailments are likely to occur will focus research, inspection and maintenance efforts to minimize their probability. RCF leads to many broken rails, and rails with severe RCF damage are difficult to inspect. Yet wear reduces the extent of crack growth and hence can be beneficial in some cases. On the other hand, wear changes wheel and rail profiles, may expose virgin material to Contact stresses, and reduces the section strength, which may lead to higher stress from bending and torsion. These influences are explored together with case studies of operational derailments. Based on this information and the current state of the art – both theoretical and practical – a number of issues are raised which need to be addressed through further developments in understanding and mitigating strategies to reduce the risk of failures from RCF and wear.
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Rolling Contact Fatigue wear and broken rail derailments
Proceedings of the 10th International Conference on Contact Mechanics and Wear of Rail Wheel Systems (CM2015), 2015Co-Authors: Eric Magel, Anders Ekberg, Peter Mutton, Ajay KapoorAbstract:Rolling Contact Fatigue (RCF) and wear are inevitable in the wheel/rail system, but resulting failures and derailments need not also be inevitable. Understanding why and under which conditions broken rails and derailments are likely to occur will focus research, inspection and maintenance efforts to minimize their probability. RCF leads to many broken rails, and rails with severe RCF damage are difficult to inspect. Wear on the other hand reduces the extent of crack growth and hence can be beneficial in some cases. On the other hand, wear changes wheel and rail profiles, may expose virgin material to Contact stresses, and reduces the section strength, which may lead to higher stress from bending and torsion. These influences are explored together with case studies of operational derailments. Based on this information and the current state of the art – both theoretical and practical – a number of issues are raised which need to be addressed through further developments in understanding and mitigating strategies to reduce the risk of failures from RCF and wear.
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wheel rail Rolling Contact Fatigue probe predict prevent
Wear, 2014Co-Authors: Anders Ekberg, Bengt Akesson, Elena KaboAbstract:With the aim of putting prediction and prevention of Rolling Contact Fatigue of wheels and rails in context, the paper sets out with a description of the phenomena. This is followed by a discussion on predictive models with emphasis on influencing factors needed to be accounted for and how these can be incorporated in a predictive model of surface and subsurface initiated Rolling Contact Fatigue (RCF). The focus is on predictive models fast enough to be integrated with multibody dynamic simulations of train–track interaction. In particular an attempt is made to highlight how current predictive models of surface initiated RCF can be extended to incorporate all affecting phenomena. The discussion on influencing factors then forms the basis for a discussion on suitable and efficient measures to maintain RCF under control. Finally the paper provides a brief summary on similarities and differences between wheel and rail damage, and an outlook of expected future trends in terms of expected damage patterns and possibilities to meet these.
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wheel rail Rolling Contact Fatigue probe predict prevent
Proceedings of the 9th International Conference on Contact Mechanics and Wear of Rail Wheel Systems (CM2012), 2012Co-Authors: Anders Ekberg, Bengt Akesson, Elena KaboAbstract:With the aim of putting prediction and prevention of Rolling Contact Fatigue of wheels and rails in context, the paper sets out with a description of the phenomena. This is followed by a discussion on predictive models with emphasis on influencing factors needed to be accounted for and how these can be incorporated in a predictive model. This forms the basis for a discussion on preventive measures. Finally a brief outlook of expected future trends is given.
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influence of short pitch wheel rail corrugation on Rolling Contact Fatigue of railway wheels
Proceedings of the Institution of Mechanical Engineers Part F: Journal of Rail and Rapid Transit, 2005Co-Authors: Jens C O Nielsen, Anders Ekberg, Roger LundenAbstract:AbstractA numerical procedure to integrate simulation of high-frequency dynamic train-track interaction and prediction of Rolling Contact Fatigue (RCF) impact is presented. Features of the included...
Yu Xiaoxiao - One of the best experts on this subject based on the ideXlab platform.
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Rolling Contact Fatigue behavior of thermal sprayed coating a review
Critical Reviews in Solid State and Materials Sciences, 2019Co-Authors: Piao Zhongyu, Wang Haidou, Xu Binshi, Yu XiaoxiaoAbstract:Rolling Contact Fatigue (RCF) of sprayed coating is complicated process relating to materials, structures, loading conditions, etc. Herein, the research works over the past decades in RCF of spraye...
