PhD Defense | Noelia Fuentes Solis | Effect of liquid metal environment on nucleation and propagation of fatigue cracks

Effect of liquid metal environment on nucleation and propagation of fatigue cracks

In the development of the next generation of nuclear reactors, the use of liquid metal coolants is being proposed in designs that increase efficiency and improve fuel usage, resulting in less radioactive waste. One of the main priorities for the viability of these technologies is the compatibility of structural materials with the liquid metal environment. In this PhD research, the fatigue resistance of the candidate structural material for MYRRHA, austenitic stainless steel 316L, was tested in a lead-bismuth eutectic (LBE) environment similar to the one expected during reactor operation. The effect of the LBE environment was assessed on three aspects of the fatigue behaviour of 316L: 1) the number of cycles to failure, known as fatigue life; 2) the initiation of fatigue cracks on the surface of the material; and 3) the propagation of fatigue cracks through the material. The effect of LBE on these processes was compared to the effect of two reference environments: vacuum, and air. The effect of LBE on the deformation mechanism of 316L is to enhance fatigue damage nucleation and fatigue crack propagation, but this is compensated by a fatigue crack growth threshold higher than in air, which causes delayed crack initiation times, and results in a fatigue life in LBE around 3 times shorter than in vacuum, but comparable to fatigue life in air. 

Promotor:

• Marc Seefeldt (KU Leuven)

SCK CEN mentors:

• Serguei Gavrilov (SCK CEN)
• Pierre Marmy (SCK CEN)

Click here for a list of obtained PhD degrees.