Capabilities

Capabilities

High-Temperature Water Splitting Materials Controlled Environment Stress and Corrosion Testing and Characterization

Laboratory

Idaho National Laboratory (INL)

Capability Expert

Gabriel Ilevbare

Class

Characterization

Node Readiness Category

2: High-Temperature Electrolysis (HTE)

Description

This capability enables elevated temperature fatigue, creep-fatigue, and crack growth testing as well as static exposures of materials in highly controlled environments to study a material's cyclic resistance, fracture mechanics, stress relaxation, and corrosion behavior. A servo-hydraulic and a servo-electric frame have been equipped with a gas-tight chamber and an integrated precision gas delivery system to feed a simulated environment at specific partial pressures. Mass flow and pressure controllers regulate the gas flow and pressure, respectively. The servo-hydraulic frame is able to perform cyclic and stress relaxation tests with its ability to operate in several control modes including strain-, load-, and stress-control and to test specimens at temperatures of up to 1000°C. It has a gas chromatograph and two solid-state hygrometers to record the gas chemistry at the inlet and outlet of the chamber and continuous feedback of the partial pressure of water is employed at the inlet hygrometry. The gas delivery system combined with the continuous feedback allows the water content to be controlled to the ppm level. Similarly the test environment in the servo-electric frame can be precisely controlled and crack growth testing may be conducted at temperature as high as 1100°C.

An inert gas flow loop is also part of this suite of equipment and is used to study the static corrosion behavior of materials in helium, and potentially other, environments. Materials can be exposed to oxidizing, carburizing, reducing, and decarburizing environments for long periods of time at temperatures as high as 1000°C in a closed-loop, feedback controlled system that pre-mixes the gas environment.

Capability Bounds‎

Cyclic, stress relaxation, and corrosion testing of laboratory-scale test specimens can be performed at temperatures from room temperature to as high as 1000°C and fracture mechanics and crack growth behavior studied at temperatures up to 1100°C. The partial pressure of water vapor in the servo-hydraulic frame is able to be controlled to as low as 5 ppm. Further modifications would be necessary to reliably control the water vapor at levels less than 5 ppm. The test space in the servo-electric frame is limited to about 75 mm diameter and 200 mm length. The helium-based flow loop would require some modification for gas environments that would be representative of the hydrogen generation process.

Unique Aspects‎

The unique aspect of this test suite is the ability to perform testing at high temperatures in environments other than air or vacuum and to precisely control the chemistries of these environments.

Availability‎

This capability is available for use at Idaho National Laboratory.

Benefit‎

Cyclic loads occur as a result of power transients in service and extended service times at high-stress during steady power operation which induce creep deformation. The combination of these two deformation modes can result in accelerated material damage and is approximated in the laboratory by creep-fatigue testing. This type of property characterization, as well as crack growth, stress relaxation, and static exposures in controlled environments, aid in understanding the influence of environmental interactions during service.

Images

References‎

Carroll, L.J., C. Cabet, R. Madland, R.N. Wright, "Creep and Environmental Effects on the High Temperature Creep-Fatigue Behavior of Alloy 617," Journal of ASTM International 8(6) 1-13 (2011).