PhD Defense | Amke Lescur | The Influence of Liquid Lead-Bismuth Environment on Mechanical Properties and Corrosion Resistance of Austenitic Stainless Steel Welds

The Influence of Liquid Lead-Bismuth Environment on Mechanical Properties and Corrosion Resistance of Austenitic Stainless Steel Welds

The new MYRRHA nuclear research reactor is being built at SCK CEN. This will be cooled with a liquid metal, namely a mixture of lead and bismuth. The reactor vessel must therefore be built with materials that are sufficiently resistant to the potentially harmful effects of this coolant. Since welds in general often behave as the weakest link, it is extremely important to also investigate their behavior in lead-bismuth. The mechanical and corrosion properties of two welds in lead-bismuth were investigated. Tensile and fracture toughness tests were performed on both the base materials and weld materials, both in air and in lead-bismuth, to investigate the influence on the mechanical behavior of the welds. Under the tested conditions, no significant influence of the lead-bismuth was found. However, when examining the base material of one of the welded plates, an amount of undesirable brittle phase was found. With a camera set-up, the local deformation behavior of the welds compared to base material was examined. The corrosion behavior was also analyzed by prolonged exposure to static and dynamic flowing lead-bismuth. It was shown that, depending on the conditions of the lead-bismuth, the welds sometimes behaved better than worse than the base material.

Promotor:

• Roumen Petrov (UGent)

Co-Promotor:

• Stijn Hertelé (UGent)

SCK CEN mentors:

• Jun Lim (SCK CEN)

• Erich Stergar (SCK CEN)

Click here for a list of obtained PhD degrees.