## 1 Introduction
Formation of dispersion hardening particles of the Ni\({}_{2}\)(Cr,Mo) ordered phase led to a reduction in the alloy's corrosion equilibrium potential, primarily due to enhanced interatomic interactions [39]. However, in a study of a model Ni-33 at. % Cr alloy corrosion, [PERSON] et al. [41] observed degradation of a Ni\({}_{2}\)Cr (MoPt\({}_{2}\)-type) long-range ordered phase within the Ni-Cr binary system. They reported that the formation of the Ni\({}_{2}\)Cr phase accelerated the corrosion process in molten chlorides. This acceleration was attributed to two primary factors: the anisotropic corrosion behavior of the LRO phase and the internal lattice strain induced by the LRO structure. In another study [42], the same authors declared that the cold-rolling process increased the susceptibility of 316 L steel to corrosion in molten FLiNaK salt. [PERSON] et al. [43] investigated the impact of microstructural changes under plasticity-imparting conditions on alloy corrosion performance in molten salts. They showed that the stored dislocations and dislocation substructures formed during high-temperature creep (HTC) facilitated mass transfer towards the corrosion-affected layer through intragranular diffusion of the alloying elements. Subsequently, the recrystallized fine-grained microstructure of the corrosion-affected layer enhanced transfer to the salt-exposed surface via intergranular diffusion. This enhanced mass diffusion accelerated molten salt corrosion of the alloy, significantly shortening its lifespan under operational conditions. However, it appears that one of the most significant microstructural changes that affects intergranular corrosion (IGC) is the formation of carbide or topologically close-packed (TCP) phases. Metallographic analysis of samples of AISI 316 steel after corrosion tests in a LiF-BeF\({}_{2}\) melt at 700 \({}^{\circ}\)C revealed the presence of grain boundary precipitation of the Cr\({}_{7}\)Cphase, thus confirming carbon and chromium diffusion towards the grain boundaries, causing subsequent initiation of IGC processes [33]. Similarly, IGC was detected in AISI 316L, 316 Ti, and 321 austenitic stainless steels after their exposure in melts based on a NaCl-KCl equimolar mixture at 750 \({}^{\circ}\)C [44]. The authors proposed a mechanism of corrosion of stainless steels in molten chlorides that includes the following stages: deposition of chromium-containing carbides along the grain boundaries and formation of galvanic pairs between the chromium-depleted parts of the grains of austenitic alloys and the carbide phases. Later, the same authors indicated that intermetallic topologically close-packed \(\chi\) phases containing chromium and molybdenum were formed in low-carbon steels as a result of heating to 750 \({}^{\circ}\)C, also inducing IGC processes [45]. The corrosion behavior of the corrosion-resistant alloy Hastelloy\({}^{\circledR}\) G-35\({}^{\circledR}\), the corrosion and heat-resistant alloy VDM\({}^{\circledR}\) Alloy 600 or Nicrofer\({}^{\circledR}\) 7216, and the corrosion-resistant alloys VDM\({}^{\circledR}\) Alloy C-4 or Nicrofer\({}^{\circledR}\) 6616 and VDM\({}^{\circledR}\) Alloy 625 or Nicrofer\({}^{\circledR}\) 6020 was also investigated in fused KCl-AlCl\({}_{3}\) at 450-650 \({}^{\circ}\)C with exposure times of up to 1000 h [46]. Increasing temperature noticeably increased the corrosion rates and changed the corrosion process nature. Transmission electron microscopy revealed that Me23 nCnC6 type carbides (for VDM\({}^{\circledR}\) Alloy 600) and intermetallic TCP phases (such as sigma-phase in case of Hastelloy\({}^{\circledR}\) G-35\({}^{\circledR}\), VDM\({}^{\circledR}\) Alloy C-4, and VDM\({}^{\circledR}\) Alloy 625) were formed during prolonged high-temperature exposure. These phenomena can accelerate intergranular corrosion and stress corrosion cracking of materials under industrial conditions.