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conferenceseries
.com
Volume 5, Issue 6 (Suppl)
J Mat. Sci.
ISSN: 2321-6212
Advanced Materials 2017
October 26-28, 2017
OCTOBER 26-28, 2017 OSAKA, JAPAN
13
TH
INTERNATIONAL CONFERENCE ON
Advanced Materials and Nanotechnology
Effects of loading frequency on cyclic deformation and fatigue behavior of metastable austenitic
stainless steels
Davi Pessoa
Technical University of Dresden, Germany
I
n order to evaluate the true durability of a material or component a sufficiently high number of fatigue tests performed at a
number of cycles higher than the classical fatigue limit must be executed, which, in turn, implies that normally pronounced
time consumption and high costs are involved. This issue can be addressed using high frequency test systems, allowing the
performance of cyclic loading tests in high to very high cycle fatigue regime in a reasonable time. However, the likely influences
of the test frequency on the material response must be considered. For this reason and because metastable austenitic steels
are well known for their strain rate sensitivity, the steel AISI 304 was analyzed regarding the influence of load frequency on
the cyclic response and fatigue behavior. Fatigue tests were performed at load frequencies of 100 Hz and 1000 Hz using two
resonance pulsation test stands, as well as by means of a servo-hydraulic test machine at 1 Hz and 50 Hz. The cyclic deformation
behavior was characterized based on the evaluation of stress-strain hysteresis loops and temperature measurements. The
deformation-induced phase transformation from γ-austenite to α'-martensite was globally and locally evaluated by means of
magneto-inductive measurements and EBSD analysis, respectively. The analyses showed that higher amounts of α'-martensite
and lower plastic strain amplitudes are observed when the cyclic experiments are carried out at lower frequency, promoting
higher fatigue strengths.
Biography
Davi Pessoa has completed a mechanical engineering and has MSc degree in materials science from Federal University of Rio Grande do Sul. He has worked for
more than 8 years in the automotive field and 4 years as Scientific Researcher in the Fraunhofer Institute for Material and Beam Technology and at the meantime
as Guest Researcher in the Technical University of Dresden and did his PhD studies. He has published 8 papers and has been serving as a Reviewer of a reputed
journal.
davi.pessoa@mailbox.tu-dresden.deDavi Pessoa, J Mat. Sci. 2017, 5:6
DOI: 10.4172/2321-6212-C1-008