HyPower: Development of alternative testing methods for evaluating material behavior under hydrogen conditions

Project description

The use of hydrogen in power plants exposes many metals to hydrogen, which can lead to hydrogen embrittlement. Extensive testing is required to assess the potential for hydrogen embrittlement in existing power plants, develop standards for metals utilized in power plants, and support the development of alloys. Hydrogen embrittlement testing is costly and time-consuming, and there are only a limited number of laboratories that can perform these tests. HyPower is investigating the suitability of three methods as alternatives to material testing in high-pressure H2 autoclaves: tests under electrolytic cathodic hydrogen loading (KATH), tests using the hollow specimen technique (HP), and tests under gaseous hydrogen preloading (GV). Three application-relevant reference materials—P355NH (1.0565), 17-4 PH (1.4542) and Alloy 617 (2.4663)—were selected in collaboration with industry representatives for the development of the alternative testing methods. In addition, the mechanisms of hydrogen embrittlement are being evaluated for each testing method. The overall goal of HyPower is to develop a testing recommendation for the future implementation of cost and time-efficient material tests depending on the material class and application issue (screening or parameter determination).

Fraunhofer IWM subproject

At Fraunhofer IWM, fatigue testing using hollow specimens is being investigated and further developed. Specimens with an inner bore filled with pressurized hydrogen are used in a classic test environment. The main advantages of this technology are the low hydrogen volume, which does not require explosion protection measures, and the fact that existing testing machines and measurement technology can continue to be used. The sample can also be easily heated and cooled from the outside. The focus is on optimizing the inner surface of the bore and the hollow specimen geometry used, as well as high-temperature hydrogen testing using Alloy 617 as a testing material.