High-temperature corrosion behaviour of metal alloys in commercial molten salts

Research output: Contribution to journalArticlepeer-review

Authors

  • Anabel Palacios
  • Aina Avila
  • Geng Qiao
  • Ernesto Mura

Colleges, School and Institutes

External organisations

  • Birmingham University
  • Global Energy Interconnection Research Institute Europe GmbH

Abstract

One of the main limitations concerning the implementation of heat transfer fluids in Concentrated Solar Power (CSP) plants, are their compatibility with the construction material. Hence, the study of this interaction over cycles is crucial for a proper material selection and life span forecast. In this work, the chemical compatibility of four commonly used metals in CSP plants; low carbon steel-A1045, stainless steel-304H and 316L, and nickel alloy-Inconel 600, with one of the most promising HTFs, Solar Salt, was evaluated. Two different methodologies (gravimetrical and descaled method) were compared and used to characterise the corrosion behaviour depending on the metal coupons analysed, concluding that the best method for most of the metals is the descaled one. The corrosion oxides were also characterized using a combination of different techniques: SEM, EDX, and XRD. Inconel 600 showed the best corrosion resistance among the metals evaluated. However, a further brief economical study concludes that a compromise between the overall metal loss cost per year and the price of the construction material over the lifetime of the plant must be found. The two stainless steels (304H and 316L) were identified as the best performing according to metal loss vs. material price and mechanical properties vs. corrosion rate.

Details

Original languageEnglish
Pages (from-to)437-452
Number of pages16
JournalSolar Energy
Volume201
Publication statusPublished - 1 May 2020

Keywords

  • Carbon steel, Concentrated solar power, High-temperature corrosion, Molten salts, Nickel alloy, Stainless steel