Presentation Title

Corrosion Behavior of Metallic Alloys in a Molten Chloride Eutectic Salt

Faculty Mentor

Vilupanur Ravi

Start Date

17-11-2018 10:15 AM

End Date

17-11-2018 10:30 AM

Location

C304

Session

Oral 2

Type of Presentation

Oral Talk

Subject Area

engineering_computer_science

Abstract

The rising demand for energy is creating an urgent need to develop an alternative method of producing electrical energy that is sustainable, cost-efficient and a clean alternative to traditional fossil fuel processes. Nuclear power is one option that has the potential to resolve these issues. The coolant fluid in a nuclear reactor must possess certain qualities such as high volumetric heat capacity, high boiling point, low vapor pressure, resistance to radiation and thermodynamic stability. In recent years, there has been an increased interest in molten salts as replacements for water as a coolant. Despite the potential for increased corrosion rates in the containment vessel, molten salts minimize the risk of explosions because they do not need to be pressurized. Fluoride salts are the preferred candidates for a coolant material, but the associated expenses and safety hazards make them unattractive for prolonged utilization. Chloride salts offer a safer and more cost-effective alternative but can be highly corrosive. Therefore, careful consideration is required in the material selection process of the containment vessel. In this project, two stainless steels (UNS S31600 and UNS S30400) and one nickel-base alloy (UNS N06601) were tested at 700℃ in a ternary molten eutectic LiCl-KCl-MgCl2 using immersion testing. The samples were

dimensioned and their masses were recorded before and after test to calculate mass loss. The data from immersion was complimented with optical microscopy and scanning electron microscopy (SEM).

Summary of research results to be presented

UNS S30400 showed the corrosion rate because it had the highest mass loss rate over a 24 h period, i.e., 3.8 mg/cm2. UNS S316 exhibited the least mass loss over the 24 h period of 1.7 mg/cm2, indicating that it had the highest corrosion resistance. The nickel-based superalloy, UNS N06601 had a mass loss of 3.5 mg/cm2 over the 24 h period, which showed that it had a corrosion resistance that was in between the two stainless steels. However, the backscattered electron micrographs show that the stainless steels had a significant amount of pits on the surface while the nickel-based alloy did not show any evidence of pitting. Therefore, the UNS N06601 alloy would be preferable to the stainless steels despite having a higher mass loss because of the absence of pitting corrosion, a localized form of corrosion the progression of which is difficult to predict.

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Nov 17th, 10:15 AM Nov 17th, 10:30 AM

Corrosion Behavior of Metallic Alloys in a Molten Chloride Eutectic Salt

C304

The rising demand for energy is creating an urgent need to develop an alternative method of producing electrical energy that is sustainable, cost-efficient and a clean alternative to traditional fossil fuel processes. Nuclear power is one option that has the potential to resolve these issues. The coolant fluid in a nuclear reactor must possess certain qualities such as high volumetric heat capacity, high boiling point, low vapor pressure, resistance to radiation and thermodynamic stability. In recent years, there has been an increased interest in molten salts as replacements for water as a coolant. Despite the potential for increased corrosion rates in the containment vessel, molten salts minimize the risk of explosions because they do not need to be pressurized. Fluoride salts are the preferred candidates for a coolant material, but the associated expenses and safety hazards make them unattractive for prolonged utilization. Chloride salts offer a safer and more cost-effective alternative but can be highly corrosive. Therefore, careful consideration is required in the material selection process of the containment vessel. In this project, two stainless steels (UNS S31600 and UNS S30400) and one nickel-base alloy (UNS N06601) were tested at 700℃ in a ternary molten eutectic LiCl-KCl-MgCl2 using immersion testing. The samples were

dimensioned and their masses were recorded before and after test to calculate mass loss. The data from immersion was complimented with optical microscopy and scanning electron microscopy (SEM).