Abstract
To research the influence of molten nitrate erosion on concrete thermal storage material, it firstly selects several main components of thermal storage concrete, makes them mixing with and soaking in molten nitrate in high temperature respectively, and then analyzes the phase transformation, and determines whether the two substances involve in chemical reaction by combining with the thermodynamic calculation results in this paper. The experiment selects the two influencing factors of erosion temperature and time, and it gives analysis from such aspects as mass and apparent morphology of the sample before and after etching. The research results indicate that the concrete does not show greater destruction after suffering three times of erosion by circulation in different temperature. However, after suffering sixty times of erosion by circulation in 450℃, the surface shows obvious crack, few peeling and pits; along with rising of erosion temperature and extension of erosion time, serpentine corrosion and iron ion oxidization in concrete aggravate, concrete aperture enlarges, and porosity increases gradually. It follows that nitrate content in concrete reduces gradually from erosion interface to the outward, and the measured value obtained by quantitative analysis with electronic probe can better coincide with the fitted value obtained by establishing one-dimensional diffusion model.
