| Title |
Feasibility Analysis and Verification of 4K Cryogenic Charpy Impact Test Method Using Liquid Helium |
| Authors |
온한용(Han-Yong On) ; 윤정환(Jeong-Hwan Yoon) ; 권준영(Jun-Yeong Kwon) ; 이기환(Gi-Hwan Lee) ; 오승준(Seung-Jun Oh) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.12.968 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Cryogenic Mechanical Properties; Liquid Helium; Cooling Method; Charpy Impact test; 316L Stainless Steel |
| Abstract |
This study investigates and validates the feasibility of a Charpy impact testing methodology
conducted at 4K ultra-cryogenic temperatures using liquid helium (LHe). Conventional cryogenic impact tests
are primarily performed at 77K using liquid nitrogen; however, with the increasing demand for hydrogen
energy systems operating at lower temperatures, evaluating mechanical properties at temperatures below
20K has become essential. In this context, a new approach was developed to cool ISO 148-1 standard 316L
stainless steel specimens by directly injecting LHe into a specially designed containment system. The injection
was performed at a pressure of 9 psig, and it was experimentally confirmed that the specimen core
temperature stabilized at approximately 4K within 45 seconds after LHe exposure. Subsequent Charpy
impact testing at this temperature demonstrated reliable and repeatable results, confirming that sufficient
thermal equilibrium had been achieved. The study not only demonstrates the technical feasibility of this
cooling approach but also provides supporting data on the stability and reproducibility of mechanical property
evaluation under ultra-low temperatures. In particular, the results offer significant insight into material
behavior relevant for components exposed to cryogenic hydrogen conditions, such as storage tanks, transfer
lines, and safety valves. The proposed methodology overcomes practical limitations of traditional testing
setups by allowing efficient specimen cooling without requiring full-system cryogenic insulation. Therefore,
this work provides a crucial reference framework for future material development and testing in support of
next-generation hydrogen infrastructure, where accurate property data under extreme cryogenic conditions
is critical for safe and efficient system design. |