Master Thesis Work, Experimental investigation and numerical modelling of the fatigue behavior of additively manufactured 316L stainless steel

Vattenfall

  • Stockholm
  • Permanent
  • Heltid
  • 1 månad sedan
About the jobBackgroundNumerous components within Swedish nuclear reactors comprise various grades of stainless steel. This material undergoes simultaneous exposure to cyclic loads from mechanically induced vibrations, thermal fluctuations and elevated temperatures.Moreover, the escalating energy demand within society underscores the critical importance of the ongoing long term operation (LTO) program for Sweden’s active nuclear power plants, ensuring the maintenance of a stable, fossil-free electricity production. The primary objective of the LTO program is to extend the operational lifespan of nuclear reactors to 60 or even 80 years. Additive manufacturing (AM) emerges as a pivotal solution in efficiently replacing stainless steel components upon reaching their designated lifetime.ObjectivesThe objective of the MSc thesis project is to enhance understanding regarding the fatigue strength of AM 316L stainless steel, considering various pretreatments and surface conditions. Additionally, the project will explore the anisotropic behavior by conducting fatigue tests using specimens printed in different orientations. An existing numerical return-mapping algorithm, with integrated anisotropic rate-independent plasticity, will be extended to capture anisotropic damage of the stainless steel in order to simulate the fatigue life with a complete constitutive framework.The present thesis work includes several activities:
  • Pre-study and literature survey
  • Experimental fatigue tests at KTH to obtain qualification data (SN-graphs) of AM specimens in solution annealed, hot isostatic pressing, machined and as-built conditions at room temperature (RT) • Experimental fatigue tests at KTH with AM specimens printed in the horizontal, 45° and vertical direction to analyze the anisotropic fatigue behavior at RT
  • Analysis of the test specimens and the AM material at the KTH laboratories
  • Return mapping modelling of anisotropic damage in Matlab
  • Study visit to the Swedish nuclear power plants
Your profileWe are looking for studento join our journey towards a fossil free future. You are soon to be graduated from your academic studies. You also identify yourself with our principles: active, open, positive and safe.
  • Education - Master's program (Mechanics, Materials Science, Mechanical Engineering, or Solid Mechanics)
  • Scope - 30hp
  • Required language skill: Swedish and English.
Additional information
  • Location: KTH, Stockholm
  • Application – a combined document with your CV and cover letter, and grades are to be submitted in the application.
  • Deadline for application is :2024-05-31.
Schedule/time-lineThe MSc thesis project will be carried out at the Material and Structural Mechanics unit in the Engineering Mechanics department at KTH Royal Institute of Technology. The project is planned to start 26th of August 2024, and finish by 20th of December 2024.SupervisorsMustafa Subasic (msubasic@kth.se) – KTHRami Mansour (rmansour@kth.se) – KTH/Aarhus UniversityJonas Faleskog (faleskog@kth.se) – KTHPål Efsing (pal.efsing@vattenfall.com) – Vattenfall (Ringhals AB)Björn Forssgren (bjorn.forssgren@vattenfall.com) – Vattenfall (Ringhals AB)Fredrik Gustavsson (fredrik1.gustavsson@vattenfall.com) – Vattenfall (Forsmarks Kraftgrupp AB)About the companyWe have been electrifying industries, powering homes and transforming life through innovation and collaboration for more than 100 years. Empowered by our goal, we are determined to enable fossil free living within one generation. To succeed we, as one of Europe's leading energy companies, must be fossil-free ourselves.But that’s not enough. That’s why we are looking beyond our own industry, to see where we can really make a difference.Join us in our journey towards a fossil-free life within one generation.Want to learn more about what we do? Visit .

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