The corrosion resistance of 316 stainless steel (316SS) in molten KCl-MgCl₂ salts was studied through static immersion corrosion at high temperatures. Below 600 °C, the corrosion rate of 316SS increased slowly with increasing temperature. When the salt temperature rises to 700 °C, the corrosion rate of 316SS increases dramatically. The corrosion of 316SS is mainly due to the selective dissolution of Cr and Fe at high temperatures. The impurities in molten KCl-MgCl₂ salts could accelerate the dissolution of Cr and Fe atoms in the grain boundary of 316SS, and purification treatment can reduce the corrosivity of KCl-MgCl₂ salts. Under the experimental conditions, the diffusion rate of Cr/Fe in 316SS changed more with temperature than the reaction rate of salt impurities with Cr/Fe.

In this work, a novel eutectic nitrate molten salt mixture of the NaNO₃-KNO₃-Ca(NO₃)₂ (16:48:36 wt%) ternary system with the significant advantage of low melting temperature was successfully designed and prepared using the static fusion method. Then, its thermal-physical properties, such as the melting point, fusion enthalpy, thermal stability, specific heat capacity, thermal diffusivity, thermal conductivity, density, and viscosity, were respectively measured by a modified or self-developed experimental device. Meanwhile, for better understanding and evaluating the heat transfer and storage performances of the material, the thermal-physical properties of this studied molten salt were further compared with those of other currently potential nitrate/nitrite systems in concentrating solar power (CSP) applications. The results proved that the newly developed NaNO₃-KNO₃-Ca(NO₃)₂ system has excellent thermal-physical properties and flow characteristics. Moreover, the cost analysis also showed the new salt has good economic performance with potential market competitiveness, its price is determined to be only 42.48 ¥/kg. All of these advantages make it a promising candidate material for heat transfer fluid (HTF) and thermal energy storage (TES) in CSP applications. This work is useful and significant for developing new molten salt materials and choosing appropriate media of HTF and TES in CSP plants or other probable thermal power generation facilities.

The corrosion behavior and cracking susceptibility of the disbonded coating in the X80 steel pipeline were investigated by different methods. The oxygen content in the trapped solution decreased rapidly with the formation of an airtight disbonded area. The airtight system affected the electrode reaction process, resulting in the inhibition of corrosion in the center of the disbonded area and the more refined surface finish of the sample. The bottom of the disbonded area underwent a relatively intense and accelerated corrosion reaction controlled by the diffusion process. The cracking susceptibility of the X80 steel firstly decreased and then increased in the pointing direction.