Corrosion Behavior of Alloys in Molten Salts for Concentrating Solar Power Plants Investigated

Strategic Insights -

Research published in the journal Solar Energy Materials and Solar Cells has provided insights into the corrosion behavior of alloys in molten salts for concentrating solar power plants. The study, conducted by a team of researchers from the Changsha University of Science and Technology, aimed to analyze the corrosion behavior of TP347H stainless steel, Haynes230, and Inconel625 alloys in a self-developed novel molten chloride salt.

The research findings show that the corrosion mechanism of the alloy samples in molten chloride salts was analyzed through microscopic characterization and elemental analysis tests. The results indicate that corrosion pits appear on the surface of the alloy samples with increasing corrosion time, and distinct corrosion cracks are observed on the surface of the Inconel625 sample. The average corrosion rate of TP347H stainless steels is 2383.628 μm/a, and those of Haynes230 and Inconel625 are 487.639 μm/a and 5437.520 μm/a, respectively. The research also found that the protective oxide layer within TP347H stainless steels corrosion layer effectively inhibited further matrix corrosion, and the superior corrosion resistance of Haynes230 can be attributed to its higher Ni and W content.

Key Takeaways:

  • The corrosion behavior of TP347H stainless steel, Haynes230, and Inconel625 alloys was investigated in a self-developed novel molten chloride salt (24.5 wt% NaCl-8.2 wt% KCl-67.3 wt% CaCl2) to ensure the long-term stability of the system.
  • The corrosion mechanism of the alloy samples in molten chloride salts was analyzed through microscopic characterization and elemental analysis tests.
  • Corrosion pits appear on the surface of the alloy samples with increasing corrosion time, and distinct corrosion cracks are observed on the surface of the Inconel625 sample.
  • The average corrosion rate of TP347H stainless steels is 2383.628 μm/a, and those of Haynes230 and Inconel625 are 487.639 μm/a and 5437.520 μm/a, respectively.
  • The protective oxide layer within TP347H stainless steels corrosion layer effectively inhibited further matrix corrosion.
  • The superior corrosion resistance of Haynes230 can be attributed to its higher Ni and W content.
  • The research aims to optimize the usage of novel molten salts and alloys to achieve long-term stability of the concentrating solar power plants.

Statistics:

  • The average corrosion rate of TP347H stainless steels is 2383.628 μm/a.
  • The average corrosion rate of Haynes230 is 487.639 μm/a.
  • The average corrosion rate of Inconel625 is 5437.520 μm/a.

Sources:

  • Corrosion Behavior of Different Alloys In Novel Chloride Molten Salts for Concentrating Solar Power Plants. Solar Energy Materials and Solar Cells, 2025; 286.
  • NewsRx. Findings on Energy Reported by Investigators at Changsha University of Science and Technology (Corrosion Behavior of Different Alloys In Novel Chloride Molten Salts for Concentrating Solar Power Plants). Energy Weekly News. July 11, 2025; p 258.