Thesis Title: Fatigue of Low Pressure Carbonitrided Steel

Abstract: In this project, alloy steels will be low pressure carbonitrided, quenched and tempered. The research directions which are being considered so far are related to bending fatigue properties and microstructure development during carbonitriding. The diffusivity of both carbon and nitrogen, including the alloying effects on diffusivity of carbon and nitrogen may be investigated. The residual stress, also important for the fatigue performance, will be analyzed through the hole drilling method. Besides the diffusivity and residual stress, the influence of alloying or microalloying elements, simultaneously with carbon and nitrogen contents in the case microstructure, may be studied. It is expected to find precipitates in the carbonitrided case; therefore, their formation and effect on case properties, as well as the amount of retained austenite are relevant for further investigation. The microstructure evolution upon tempering of carbonitrided steels could also be explored, particularly precipitation and recovery processes.

Degree Plan: Doctorate of Philosophy

Completion: August 2019
Group: Bar
Steel Center Student Since: August 2015

Bio: Larissa joined the ASPPRC in August 2015 after completing her Master of Science degree in Mechanical Engineering at the Pontifical Catholic University of Minas Gerais, Brazil. Before that, she worked for 2 years at National Oilwell Varco (NOV), in Oil & Gas industry. Prior to working at NOV, she had completed her Bachelor of Engineering degree, in Mechanical Engineering, also at the Pontifical Catholic University of Minas Gerais, Brazil.

Office: 215