PhD opportunities

Modelling the effects of quenching and tempering on the microstructure and the fracture properties of 16-20MnNiMo5-type low alloy steels

Thesis proposal

Area of expertiseSciences et génie des matériaux
Doctoral SchoolISMME - Ingénierie des Systèmes, Matériaux, Mécanique, Énergétique
SupervisorGOURGUES Anne-Françoise
Research unitCentre des Matériaux
KeywordsBainite, brittle cleavage cracking, microstructure, local approach to fracture
AbstractThe increase of power of the most recent nuclear reactors comes with an increase of the size of the heavy forgings constitutive of the components of the primary circuit. This tends to induce some heterogeneity of the constitutive low alloy steel, both in terms of microstructure and mechanical properties. One of the reasons for such a heterogeneity is the difference in cooling rate between the skin and the core of large thickness components during quenching. A systematic study of the influence of quenching and tempering parameters on the microstructure and mechanical properties of a given low alloy steel started during a previous PhD project (planned to be defended in 2023). The results allow sketching different trends that must be refined during the resent research project.
Hence, new relevant microstructural observations and mechanical characterizations will be performed and expanded to all available heat treatment configurations of the material. The quantitative analysis of these experimental results will then provide the necessary data to improve a local approach to fracture model that will explicitly rely on metallurgical parameters at the origin of the brittle failure of these steels. This model should be able to reproduce the influence of final heat treatments on through thickness variations of mechanical properties in heavy forged components.
ProfileEngineer and / or Master of Science - Good level of general and scientific culture. Good level of knowledge of French (B2 level in french is required) and English. (B2 level in english is required) Good analytical, synthesis, innovation and communication skills. Qualities of adaptability and creativity. Teaching skills. Motivation for research activity. Coherent professional project.

Prerequisite (specific skills for this thesis):
Metallurgy, mechanics of materials. Experience in the field of fracture and/or in finite element modeling would be appreciated.



Applicants should supply the following :
• a detailed resume
• a copy of the identity card or passport
• a covering letter explaining the applicant’s motivation for the position
• detailed exam results
• two references : the name and contact details of at least two people who could be contacted
• to provide an appreciation of the candidate
• Your notes of M1, M2
• level of English equivalent TOEIC

to be sent to recrutement_these@mat.mines-paristech.fr
FundingContrat de recherche