Initiation and early growth of short fatigue cracks at inclusions

Kaynak, Cevdet
Baker, TJ
In this study, the initiation and early growth behaviour of short fatigue cracks in En7A steel with a high content of elongated MnS inclusions was investigated by generating and evaluating data on the growth of short fatigue cracks under various stress levels and stress ratios for the six principal specimen orientations. Short cracks usually initiated at the debonded interfaces between the matrix and the inclusions. If there was no debonding, cracking sometimes occurred in the inclusions. In the early stages, short cracks propagated by a mechanism of inclusion influenced growth. Under low stress levels, usually one short crack was initiated which dominated most of the fatigue life, while under high stress levels there was multicrack interaction. (C) 1996 The institute of Materials.


Inclusion induced anisotropy of short fatigue crack growth in steel
Kaynak, Cevdet; Baker, TJ (Informa UK Limited, 1996-07-01)
In this study, the growth behaviour of short fatigue cracks in En7A steel with a high content of elongated MnS inclusions was investigated by generating and evaluating the short crack data under different loading conditions for the six principal specimen orientations. Short cracks showed a strong anisotropic behaviour in which they grew much faster in the transverse and short transverse orientations than in the longitudinal orientations in all fatigue processes. This was due to the relatively high content o...
HUSAIN, Z (Elsevier BV, 1989-11-01)
The initiation and growth of fatigue microcracks in a BS 4368-500 structural steel has been studied in laboratory air and in aerated 3.5% NaCl solution. Experiments were performed using constant load fully reversed bending at a frequency of 25 Hz. Particular emphasis has been placed on the role of inclusions in crack initiation and growth. The fatigue strength of the material reduced in the aqueous environment to 130 MPa compared with 290 MPa in air. In air, microcracks initiated at oxide inclusions by the ...
Effect of tube spinning and subsequent heat treatments on strength, microstructure and residual stress state of AISI/SAE type 4140 steel
Gür, Cemil Hakan (Informa UK Limited, 2003-11-01)
In the present study, the effects of deformation percentage (23, 30, 50 and 66%) and subsequent stress relief and tempering heat treatments on the mechanical properties, residual stress state and microstructure of AISI/SAE type 4140 steel tubes manufactured by forward spinning were evaluated. Mechanical properties were determined by means of hardness and tensile tests. The tangential component of the surface residual stresses was determined by a slitting method. Plastic deformation of the metal during spinn...
Twinning-induced shear banding and its control in rolling of magnesium
Atik, Kubra; Efe, Mert (Elsevier BV, 2018-05-16)
Rolling of magnesium sheets is challenging at temperatures below 200 degrees C due to the strain localization and shear banding associated with the twinning activity. In this study, magnesium sheets with basal, off-basal (90 degrees tilted), and mixed (50% basal + 50% off-basal) textures are rolled between room temperature and 165 degrees C to understand and control the twinning-induced localizations. While the fraction of strain-localized regions increases from 0.1 to 0.6 with strain and temperature, the i...
Some peculiarities of nematic-isotropic liquid phase transitions in monomorphic and polymorphic mesogens
Nesrullajev, Arif; Yurtseven, Hasan Hamit; Saliholu, Selami; Kazanc, Nadide (Elsevier BV, 2002-10-03)
In this study, the dynamics of the changes of the morphological properties in the nematic mesophase and in the heterophase regions of the phase transitions between the nematic mesophase and the isotropic liquid for the thermotropic mesogens have been investigated. Experimentally, we have obtained the thermal hysteresis for the investigated phase transitions. For the analysis of the phase transition temperatures and the peculiarities of the heterophase regions, the mean field theory has been used.
Citation Formats
C. Kaynak and T. Baker, “Initiation and early growth of short fatigue cracks at inclusions,” MATERIALS SCIENCE AND TECHNOLOGY, pp. 421–426, 1996, Accessed: 00, 2020. [Online]. Available: