Detail publikačního výsledku

The Effect of Prior Surface Roughness on Fatigue Life of Nitrided Specimens

KIANICOVÁ, M.; ŠANDERA, P.; HORNÍKOVÁ, J.; KOTTFER, D.; POKLUDA, J.

Originální název

The Effect of Prior Surface Roughness on Fatigue Life of Nitrided Specimens

Anglický název

The Effect of Prior Surface Roughness on Fatigue Life of Nitrided Specimens

Druh

Stať ve sborníku v databázi WoS či Scopus

Originální abstrakt

The effect of surface roughness of virgin specimens (prior roughness) made of low- alloyed high strength steel on their fatigue life after the case-hardening treatment was studied by rotating bending tests of virgin and nitrided samples. In a whole range of S-N curves, the fatigue strength of virgin samples after lathe-turning machining (high roughness) was naturally much higher than that of samples after grinding (low roughness). As expected, the fatigue strength of nitrided specimens was higher than that of virgin samples when averaged through the whole fatigue life range. When distinguishing the rough and smooth nitrided samples, the low-cycle fatigue strength of rough samples revealed to be lower than that of the smooth ones and vice a versa in the high-cycle region. This could be explained by the fact that, in the low cycle region, the cracks in the rough samples nucleated from deep surface defects while, in the smooth specimens, they nucleated from shallow defects (or as fish eyes) which prolonged their initiation stage. Almost all cracks in the high cycle region initiated as fish-eyes but the extent of nitrided layers in the rough specimens was slightly higher than that in the smooth specimens. Therefore, the fish-eye centers were shifted further to the interior of the rough specimens which increased their fatigue life.

Anglický abstrakt

The effect of surface roughness of virgin specimens (prior roughness) made of low- alloyed high strength steel on their fatigue life after the case-hardening treatment was studied by rotating bending tests of virgin and nitrided samples. In a whole range of S-N curves, the fatigue strength of virgin samples after lathe-turning machining (high roughness) was naturally much higher than that of samples after grinding (low roughness). As expected, the fatigue strength of nitrided specimens was higher than that of virgin samples when averaged through the whole fatigue life range. When distinguishing the rough and smooth nitrided samples, the low-cycle fatigue strength of rough samples revealed to be lower than that of the smooth ones and vice a versa in the high-cycle region. This could be explained by the fact that, in the low cycle region, the cracks in the rough samples nucleated from deep surface defects while, in the smooth specimens, they nucleated from shallow defects (or as fish eyes) which prolonged their initiation stage. Almost all cracks in the high cycle region initiated as fish-eyes but the extent of nitrided layers in the rough specimens was slightly higher than that in the smooth specimens. Therefore, the fish-eye centers were shifted further to the interior of the rough specimens which increased their fatigue life.

Klíčová slova

Nitriding, Surface roughness, Fatigue life, Fish-eye cracks, Surface cracks.

Klíčová slova v angličtině

Nitriding, Surface roughness, Fatigue life, Fish-eye cracks, Surface cracks.

Autoři

KIANICOVÁ, M.; ŠANDERA, P.; HORNÍKOVÁ, J.; KOTTFER, D.; POKLUDA, J.

Rok RIV

2021

Vydáno

16.11.2020

Nakladatel

TransTech Publication

Místo

Švýcarsko

ISBN

978-3-0357-1612-2

Kniha

Metallography XVII

ISSN

1662-9507

Periodikum

Defect and Diffusion Forum

Svazek

405

Číslo

1

Stát

Švýcarská konfederace

Strany od

271

Strany do

276

Strany počet

6

BibTex

@inproceedings{BUT161716,
  author="KIANICOVÁ, M. and ŠANDERA, P. and HORNÍKOVÁ, J. and KOTTFER, D. and POKLUDA, J.",
  title="The Effect of Prior Surface Roughness on Fatigue Life of Nitrided Specimens",
  booktitle="Metallography XVII",
  year="2020",
  journal="Defect and Diffusion Forum",
  volume="405",
  number="1",
  pages="271--276",
  publisher="TransTech Publication",
  address="Švýcarsko",
  doi="10.4028/www.scientific.net/DDF.405.271",
  isbn="978-3-0357-1612-2",
  issn="1662-9507"
}