Damage evolution around white etching layer during uniaxial loading
Artikel i vetenskaplig tidskrift, 2019

Rolling contact fatigue cracks and thermally induced defects are common problems in the railway industry especially as demands for increasing loads, speeds, and safety continue to rise. Often, the two types of defects are found together in the field, however, whether one causes the other to occur is not completely agreed upon. The effect of thermal damage, in the form of a martensite spot on pearlitic steel test bars, on the fatigue life in uniaxial low cycle fatigue experiments was investigated by the authors. However, the focus of the current work was to characterize the damage evolution from the low cycle fatigue (LCF) tests and correlate the crack initiation and propagation with the initial thermal damage. Residual stress measurements, digital image correlation, and X-ray tomography were used to characterize the effects of the thermal damage before, during, and after fatigue testing, respectively. It was found that the thermal damage causes strain accumulation and crack initiation at the interface between the two materials. The strain evolution was visualized using digital image correlation (DIC), clearly showing the strain concentrations at the top and bottom of the white etching layers (WEL), where the residual stresses are also most tensile. X-ray tomography confirmed the planar crack growth from the martensite spot.

rolling contact fatigue

strain localization

X-ray tomography

residual stresses

digital image correlation

white etching layer

Författare

Casey Jessop

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Johan Ahlström

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Christer Persson

Chalmers, Industri- och materialvetenskap, Konstruktionsmaterial

Yubin Zhang

Danmarks Tekniske Universitet (DTU)

Fatigue and Fracture of Engineering Materials and Structures

8756-758X (ISSN) 1460-2695 (eISSN)

Vol. In Press

Ämneskategorier

Teknisk mekanik

Bearbetnings-, yt- och fogningsteknik

Annan materialteknik

DOI

10.1111/ffe.13044

Mer information

Senast uppdaterat

2019-10-21