“Brown etching layer”: A possible new insight into the crack initiation of rolling contact fatigue in rail steels?

Li, Shaoguang; Wu, Jun; Petrov, Roumen; Li, Zili; Dollevoet, Rolf; Sietsma, Jilt

doi:10.1016/j.engfailanal.2016.03.019

Cited by 54 publications

(31 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Correlations of BEL and WEL are indicated by the observations of similar lamellar features crossing the boundaries of the layers (BEL or WEL) and the pearlitic matrix [14]. As a consequence, nanometer size grains and zones with high dislocation densities are also possible within the BEL, referring to the microstructural features of WEL, cf.…”

Section: Discussionmentioning

confidence: 90%

“…From the morphology comparison, it appears that BEL might be correlated to WEL. Assuming that BEL has martensitic microstructure and considering the fact that BEL is significantly softer (450 HV-max 752 HV) than the reported WEL with a hardness in the range between 700 HV and 1200 HV [14], it is very likely that BEL is the decomposition product of martensite. As a consequence, carbides are not observed at the used magnification in the orientation maps.…”

Section: Discussionmentioning

confidence: 93%

“…The studied brown etching layer (BEL) is a new type white etching layer (WEL) [14]. Unlike white colour of WEL, BEL etches white and brown under unpolarised light reflection, after etching with 2% Nital.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 1: (a) Optical image of brown etching layer (BEL), which was studied in this work. The same BEL can also be found in [14]. The open square indicates the area of the EBSD scan; (b) A thin lamella extracted from the area indicated by the filled square in (a) by lift out method for TEM sample preparation with focuses ion beam (FIB) milling.…”

Section: Methodsmentioning

confidence: 98%

“…A possible new type of WEL, which is etched brown colour [14], was investigated in this study, see Figure 1(a). It is named as brown etching layer (BEL), in order to be differentiated from the widely reported WEL.…”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Characterization of structural change in rail surface using advanced automatic crystallographic orientation microscopy

Petrov

et al. 2016

WIT Transactions on the Built Environment

View full text Add to dashboard Cite

Surface structural changes, formed during wheel/rail contact, in R260Mn grade rails were investigated by electron backscatter diffraction (EBSD), transmission Kikuchi diffraction (TKD) in scanning electron microscope (SEM) and automatic crystal orientation mapping in transmission electron microscope (ACOM-TEM).Grain fragmentation and refinement of ferrite are characterized by all applied methods as well as grain alignment towards traffic direction. Substructures, having misorientation lower than 5°, are identified by kernel average misorientation (KAM). Detection of retained austenite indicates martensitic nature of the structural change observed in the heavily deformed surface layer.

show abstract

Section: Discussionmentioning

confidence: 90%

Section: Discussionmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Characterization of structural change in rail surface using advanced automatic crystallographic orientation microscopy

Petrov

et al. 2016

WIT Transactions on the Built Environment

View full text Add to dashboard Cite

show abstract

Severe Plastic Deformed Zones and White Etching Layers Formed During Service of Railway Wheels

Freisinger

Rojacz

Trausmuth

et al. 2023

Metallogr. Microstruct. Anal.

View full text Add to dashboard Cite

The near-surface regions of rail wheels experience a complex thermo-mechanical loading, which varies along the location of the tread and causes severe changes to the microstructure. Occasionally, brittle white etching layers (WEL) are formed, representing a high risk of wheel damage. Therefore, we studied the depth-evolution of the surface-near microstructure along different regions of the tread of a wheel being ~ 200,000 km in service. The microstructural variations point toward a higher thermal loading history in the middle of the tread and predominant mechanical loading in the neighboring regions, where a severe plastic deformed microstructure with rolling contact fatigue cracks is present. Varieties of WEL-like microstructures were investigated, the presented analysis contributes to the knowledge of their microstructural characteristics and outpoints these regions in terms of potential crack initiation sites on railway wheels.

show abstract

Influence of white etching layer on rolling contact behavior at wheel-rail interface

et al. 2020

View full text Add to dashboard Cite

The existence of narrow and brittle white etching layers (WELs) on the rail surface is often linked with the formation of rail defects such as squats and studs, which play the key roles in rail surface degradation and tribological performance. In the present study, a systematic investigation on stress/strain distribution and fatigue life of the WEL during wheel-rail rolling contact was conducted based on a numerical model considering the realistic wheel geometry. This is the first study considering the influence of rail materials, loading pressure, frictional condition, WEL geometry (a/b), and slip ratio (Sr) in the practical service conditions at the same time. The results revealed much higher residual stress in WEL than in rail matrix. Stress changes along the rail depth matched with the previously reported microstructure evolutions. The current work revealed that the maximum difference in contact stress between the wheel passages of rail matrix and the WEL region (noted as stress variation) rises with the increase of loading pressure, the value of a/b, and Sr; but drops with the friction coefficient (μ). In addition, a critical length-depth ratio of 5 for a/b has been found. The fatigue parameter, FP, of the WEL decreased quickly with the length-depth ratio when it was less than 5 and then increased slightly when it was larger than 5. This study also revealed that the fatigue life of the WEL was reduced for high strength head hardened (HH) rail compared with standard carbon (SC) rail.

show abstract

“Brown etching layer”: A possible new insight into the crack initiation of rolling contact fatigue in rail steels?

Cited by 54 publications

References 30 publications

Characterization of structural change in rail surface using advanced automatic crystallographic orientation microscopy

Characterization of structural change in rail surface using advanced automatic crystallographic orientation microscopy

Severe Plastic Deformed Zones and White Etching Layers Formed During Service of Railway Wheels

Influence of white etching layer on rolling contact behavior at wheel-rail interface

Contact Info

Product

Resources

About