2020 Virtual undergraduate Research symposium

Retained Austenite to Increase the Fatigue Life of Transmission Gears


PROJECT NUMBER: 72

AUTHOR: Nathan Fripp, Metallurgical and Materials Engineering | MENTOR: Kip Findley, Metallurgical and Materials Engineering

 

ABSTRACT

Carburized steel components play a crucial role in power transmission systems, bur can experience fatigue failure during service. Complex microstructural gradients along with residual stresses strongly influence the mechanical performance of these components. The complexity further increases due to the deformation-induced transformation of austenite to martensite in the steel. A study was done to understand the effects of different amounts of retained austenite (RA) on the mechanical performance of the carburized microstructure. Commercial 52100 steel, a high carbon alloy, was used as a proxy for the case of carburized gears in transmission systems. The samples were heat treated to austenitizing temperatures and cryo-quenched. The RA phase fraction decreased with lower quenching temperatures. Uniaxial tensile loading on the samples will determine the effects of the amount of RA on the strength of the microstructure. In-situ feritscope measurements will evaluate the deformation-induced RA-to-martensite phase transformation. Postmortem x-ray diffraction will quantify the final phase fraction of RA in the gauge section. Future testing will include rotating bending fatigue tests to determine the ideal fraction of RA to maximize the fatigue life of the carburized components. The expected result of this research is longer life steel components for the gear trains of large power transmission systems.

 

VISUAL PRESENTATION

 

AUTHOR BIOGRAPHY

Nathan Fripp is a sophomore majoring in the Metallurgical and Materials Engineering and minoring in Public Affairs from the McBride Honors Program. He conducted research with Professor Findley and Milan Agnani, a graduate student, on the role of retained austenite on gear fatigue. He enjoyed working the research process and is eager to get back into the lab.

 


1 Comment

  1. A few definitions were a little unclear; but, overall, your presentation was clear and flowed well.

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