Rolling contact fatigue

From HandWiki - Reading time: 3 min


Short description: Deformation mechanism
Overview of bearing components, including bearing element and inner ring[1]

Rolling Contact Fatigue (RCF) is a phenomenon that occurs in mechanical components relating to rolling/sliding contact, such as railways, gears, and bearings.[2] It is the result of the process of fatigue due to rolling/sliding contact.[2][3] The RCF process begins with cyclic loading of the material, which results in fatigue damage that can be observed in crack-like flaws, like white etching cracks.[2] These flaws can grow into larger cracks under further loading, potentially leading to fractures.[2][4]

In railways, for example, when the train wheel rolls on the rail, creating a small contact patch that leads to very high contact pressure between the rail and wheel.[2] Over time, the repeated passing of wheels with high contact pressures can cause the formation of crack-like flaws that becomes small cracks.[2] These cracks can grow and sometimes join, leading to either surface spalling or rail break, which can cause serious accidents, including derailments.[2][4]

RCF is a major concern for railways worldwide and can take various forms depending on the location of the crack and its appearance.[2] It is also a significant cause of failure in components subjected to rolling or rolling/sliding contacts, such as rolling-contact bearings, gears, and cam/tappet arrangements.[5] The alternating stress field in RCF can lead to material removal, varying from micro- and macro-pitting in conventional bearing steels to delamination in hybrid ceramics and overlay coatings.[5]

Basics

Testing

Testing for RCF involves several methods, each designed to simulate the conditions that cause RCF in a controlled environment. Here are some of the methods used:

  • Twin-Disc Stands: This method uses two discs to simulate the wear the occur for rails and wheels.
  • Scaled RCF Tests: These tests use two discs of different diameters.[6]
  • Three-Ball-on-Rod Tester: This is an economical RCF proof of concept test. It is performed to evaluate the influence of heat treatment, material, lubricant, and coatings on fatigue life.[6]
  • Lundberg-Palmgren Theory and ISO 281 Based Method: This method evaluates RCF reliability considering the contact load, the geometric parameters of contact pairs, the oscillation amplitude, the RCF reliability, and the material properties.[7]

See also

References

  1. Curd, M. E.; Burnett, T. L.; Fellowes, J.; Donoghue, J.; Yan, P.; Withers, P. J. (2019-08-01). "The heterogenous distribution of white etching matter (WEM) around subsurface cracks in bearing steels". Acta Materialia 174: 300–309. doi:10.1016/j.actamat.2019.05.052. ISSN 1359-6454. Bibcode2019AcMat.174..300C. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Kapoor, Ajay; Salehi, Iman; Asih, Anna Maria Sri (2013), Wang, Q. Jane; Chung, Yip-Wah, eds. (in en), Rolling Contact Fatigue (RCF), Boston, MA: Springer US, pp. 2904–2910, doi:10.1007/978-0-387-92897-5_287, ISBN 978-0-387-92897-5, https://doi.org/10.1007/978-0-387-92897-5_287, retrieved 2024-03-14 
  3. "Rolling Contact Fatigue – About Tribology" (in en-US). https://www.tribonet.org/wiki/rolling-contact-fatigue/. 
  4. 4.0 4.1 Kang, Young Sup (2013), Wang, Q. Jane; Chung, Yip-Wah, eds. (in en), Rolling Bearing Contact Fatigue, Boston, MA: Springer US, pp. 2820–2824, doi:10.1007/978-0-387-92897-5_375, ISBN 978-0-387-92897-5, https://doi.org/10.1007/978-0-387-92897-5_375, retrieved 2024-03-14 
  5. 5.0 5.1 Ahmed, R.. "Rolling Contact Fatigue". https://home.eps.hw.ac.uk/~mcera/Publications/Books/ASM-Handbook.pdf. 
  6. 6.0 6.1 Šmach, Jiří; Halama, Radim; Marek, Martin; Šofer, Michal; Kovář, Libor; Matušek, Petr (December 2023). "Two Contributions to Rolling Contact Fatigue Testing Considering Different Diameters of Rail and Wheel Discs" (in en). Lubricants 11 (12): 504. doi:10.3390/lubricants11120504. ISSN 2075-4442. 
  7. Hai, Gao Xue; Diao, Huang Xiao; Jing, Hong Rong; Hua, Wang; Jie, Chen (2012). "A Rolling Contact Fatigue Reliability Evaluation Method and its Application to a Slewing Bearing". Journal of Tribology 134. doi:10.1115/1.4005770. https://doi.org/10.1115/1.4005770. Retrieved 2024-03-14. 




Licensed under CC BY-SA 3.0 | Source: https://handwiki.org/wiki/Engineering:Rolling_contact_fatigue
1 views |
↧ Download this article as ZWI file
Encyclosphere.org EncycloReader is supported by the EncyclosphereKSF