Font Size:
Effect of Surface Finish on Fatigue of Stainless Steels
Last modified: 2013-05-03
Abstract
The effect of surface finish on fatigue limit of Type 304 austenitic stainless steels
has been investigated. Fatigue specimens with different surface conditions were
obtained by changing the final cutting condition of lathe-turning. The surfaces and
near surface microstructures were characterised by electron backscatter diffraction
(EBSD), surface profilometry, hardness testing and X-ray diffraction for residual
stress measurement. The fatigue limits were determined using a rotating-bending
machine by means of the staircase method. Machined samples were compared
with samples annealed to remove residual stresses, and also samples that were
annealed and electro-polished. Arrested crack nuclei in run-out (>107 cycles)
fatigue tests were observed. The residual stress measured at the surface was found
to be the dominant parameter, which changes the fatigue limit relative to that of
electropolished and annealed microstructures. The effect of surface roughness is
negligible.
has been investigated. Fatigue specimens with different surface conditions were
obtained by changing the final cutting condition of lathe-turning. The surfaces and
near surface microstructures were characterised by electron backscatter diffraction
(EBSD), surface profilometry, hardness testing and X-ray diffraction for residual
stress measurement. The fatigue limits were determined using a rotating-bending
machine by means of the staircase method. Machined samples were compared
with samples annealed to remove residual stresses, and also samples that were
annealed and electro-polished. Arrested crack nuclei in run-out (>107 cycles)
fatigue tests were observed. The residual stress measured at the surface was found
to be the dominant parameter, which changes the fatigue limit relative to that of
electropolished and annealed microstructures. The effect of surface roughness is
negligible.
Full Text:
PDF