Analysis of wear debris in rolling contact fatigue cracks of pearlitic railway wheels
Journal article, 2014

In the current study a severe subsurface crack network in a railway wheel has been studied and compared to typical rolling contact fatigue cracks found in the wheel tread surface. Microstructural characteristics, chemical composition and microhardness within the cracks and around crack faces were examined. While the two damage types are principally different, both showed similar crack characteristics, with short cracks branching along the main crack paths and a discontinuous sheared layer of wear debris and metallic flakes within them. Analyses of the wear debris showed that it does not originate from external contamination or being the result of corrosion primarily. Instead it has most likely been produced by shear deformation and wear mechanisms within crack faces caused by mixed-mode crack growth. Although microstructural appearance at lower magnification seemed to differ from the bulk material, at high magnification a lamellar structure was observed consisting of layers of deformed metallic flakes and particles of the base metal. Auger electron spectroscopy was used to analyze these sheared layers; higher concentration of oxygen was measured in between flakes, indicating the presence of oxides and flakes being of similar chemical composition as the base material. A possible explanation is that these layers are created due to high shear forces and friction between crack faces in the service of the wheel. With continued rolling the material being sheared by the cyclic relative motion of the crack faces disintegrates into smaller wear debris particles with concurrent oxidation.

Mixed-mode crack growth

Pearlite

Railway

Fatigue

Internal crack friction

Author

[Person 0fdb23b3-024d-4120-9f6c-826c11540627 not found]

Chalmers, Materials and Manufacturing Technology, Materials Technology

[Person 0679d6b4-6e15-45bc-830d-a731bfcfd875 not found]

Chalmers, Materials and Manufacturing Technology, Materials Technology

[Person 35b9d899-a31c-4f50-ba69-b1e6e1668a6f not found]

Chalmers, Materials and Manufacturing Technology, Surface and Microstructure Engineering

[Person 7e40e5e2-0b6f-4860-8883-e1159c384fe7 not found]

Chalmers, Materials and Manufacturing Technology, Materials Technology

Wear

0043-1648 (ISSN)

Vol. 314 1-2 51-56

Driving Forces

Sustainable development

Subject Categories

Tribology

Applied Mechanics

Manufacturing, Surface and Joining Technology

Other Materials Engineering

Vehicle Engineering

Areas of Advance

Transport

Materials Science

Roots

Basic sciences

DOI

10.1016/j.wear.2013.11.049

More information

Created

10/8/2017