In this work, the conditions for the occurrence of Liquid Metal Embrittlement (LME) in the ferritic-martensitic steel T91 in contact with lead, Pb, were examined. Slow tensile tests with notched specimens revealed that in a temperature range close to the melting point of Pb, the steel is sensitive to LME (350–400 °C) and to Solid Metal Induced Embrittlement (SMIE) (300 °C). The cracking was stimulated by wetting (using a chemical flux) and the notch effect. It was found that the multi axial stresses state and the high level of plastic strain in front of the notch were the key factors triggering crack initiation.

The austenitic steel 15-15Ti is being considered as one of the candidate materials for internal structural components of future heavy liquid metal (HLM) nuclear systems. This work studies the steel compatibility with liquid PbBi. Constant extension rate tensile (CERT) tests of tapered specimens were used to study sensitivity to liquid metal embrittlement (LME) and crack initiation. The taper creates a variation of stress along the gauge length which allows the identification of the stress and strain for the crack appearance. Testing was performed in air and in PbBi with 10⁻⁶ to 10⁻¹² wt % oxygen content at 300 °C. Post-test observation by scanning electron microscopy (SEM) highlighted the crack morphology. An evaluation of the environmental effect on the crack initiation is presented.

The environmental performance of structural materials (e.g., corrosion and environmental assisted cracking) is one of the critical issues being addressed in the development of Generation IV fast reactors. This work aims to support the study of the performance of the ferritic-martensitic steel T91 in liquid lead, under close to operation conditions, in order to assess its suitability for an application in lead fast reactors. T91 steel was tested in air and liquid lead at 400 °C using static and slow loading regimes. Applied stresses were chosen to be slightly above the yield strength in order to evaluate the threshold stress and strain for crack initiation. Three-point bending static exposure and constant extension tests of tapered specimens were performed. Post-test surfaces and cross sections of specimens were observed using scanning electron microscopy techniques in order to detect cracks and to analyze oxide layers. The effect of strain rate of the oxide layer cracking was observed. In conclusion, T91 was not susceptible to liquid metal embrittlement, a special case of environmentally assisted cracking under the testing conditions. The cracking conditions are discussed based on previous experience.

The work is aimed on the NiCr-Cold spray coating applied on GOST 08CH18N10T steel and GOST 22K steel. Cold spray coating shows a high cohesion even as a few millimeter thick layer, therefore it has potential for the repairs not only of the energy industry components. Applied on the steel substrate, the cold spray can be considered as a bimetallic material for the purpose of the mechanical properties evaluation. Performed comparison based on tensile mechanical properties at room temperature and at 350 °C of separate steels and cold spray versus bimetallic combination is discussed. The main goal is to find the optimal approach of bimetallic material evaluation. Additional metallographic and microstructural analysis is attached to show the differences between the used combinations. Influence of possible heat treatment on the mechanical and adhesive properties is also included.

The presented paper is focused on laser shock-peening technology for hardening the metallic material surface. The material surface hardening improve fatigue performance, static properties, and resistance to stress corrosion cracking of metallic material, which is achieved by creating a pressure residual stress with. The hardening is achieved by shock waves, which are generated by confining the laser-induced plasma to cause a large pressure shock wave over a significant surface area. In the present study, effects of laser shock peening (LSP) on static and dynamic mechanical properties of austenitic stainless steel for nuclear industry were investigated. The tested material was austenitic stainless steel GOST 08CH18N10T (AISI 321H-UNS S32109) for nuclear industry (water–water energetic reactors).