Abstract
A case study was conducted on the cooling pipe of a pre-cooler which had been used in a 70-MPa hydrogen station demonstration project. The cooling pipe consisted of a main pipe, a mechanical joint pipe and a mechanical joint. The main and mechanical joint pipes had been joined using TIG welding. Through chemical composition analysis, microstructure observation and Vickers hardness measurement, it was revealed that the main and mechanical joint pipes had been manufactured from SUS316L and that 316L was the filler metal used for TIG welding. Round-bar specimens were machined out of the main pipe in order to investigate the tensile properties of the base metal. On the other hand, both round-bar specimen without reinforcement and square-bar specimens with reinforcement were fabricated from the weld-joint. Using the three types of specimens, slow strain rate tensile tests were performed in 0.1 MPa nitrogen gas and in 115 MPa hydrogen gas at a temperature of -40 °C. Reduction of area (RA), φ, for the round base-metal specimen, the round weld-joint specimen and the square weldjoint specimen were respectively, 83.5 %, 71.3 % and 81.4 % in nitrogen gas, whereas the related values in hydrogen gas were 60.1 %, 61.3 % and 40.1 %. In other words, the RA for the three types of specimens was smaller in hydrogen gas than in nitrogen gas. Dimples were formed on the fracture surfaces of the three specimen types in nitrogen gas, whereas both dimples and quasi-cleavages were formed in hydrogen gas.
| Original language | English |
|---|---|
| Title of host publication | Materials and Fabrication |
| Publisher | American Society of Mechanical Engineers (ASME) |
| ISBN (Electronic) | 9780791858004 |
| DOIs | |
| Publication status | Published - Jan 1 2017 |
| Event | ASME 2017 Pressure Vessels and Piping Conference, PVP 2017 - Waikoloa, United States Duration: Jul 16 2017 → Jul 20 2017 |
Publication series
| Name | American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP |
|---|---|
| Volume | 6B-2017 |
| ISSN (Print) | 0277-027X |
Other
| Other | ASME 2017 Pressure Vessels and Piping Conference, PVP 2017 |
|---|---|
| Country | United States |
| City | Waikoloa |
| Period | 7/16/17 → 7/20/17 |
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All Science Journal Classification (ASJC) codes
- Mechanical Engineering
Cite this
A case study of a cooling pipe for a pre-cooler used in a 70-MPa hydrogen station. / Okazaki, Saburo; Hamada, Shigeru; Itoga, Hisatake; Matsunaga, Hisao; Nakamura, Masami; Matsuoka, Saburo.
Materials and Fabrication. American Society of Mechanical Engineers (ASME), 2017. (American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP; Vol. 6B-2017).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - A case study of a cooling pipe for a pre-cooler used in a 70-MPa hydrogen station
AU - Okazaki, Saburo
AU - Hamada, Shigeru
AU - Itoga, Hisatake
AU - Matsunaga, Hisao
AU - Nakamura, Masami
AU - Matsuoka, Saburo
PY - 2017/1/1
Y1 - 2017/1/1
N2 - A case study was conducted on the cooling pipe of a pre-cooler which had been used in a 70-MPa hydrogen station demonstration project. The cooling pipe consisted of a main pipe, a mechanical joint pipe and a mechanical joint. The main and mechanical joint pipes had been joined using TIG welding. Through chemical composition analysis, microstructure observation and Vickers hardness measurement, it was revealed that the main and mechanical joint pipes had been manufactured from SUS316L and that 316L was the filler metal used for TIG welding. Round-bar specimens were machined out of the main pipe in order to investigate the tensile properties of the base metal. On the other hand, both round-bar specimen without reinforcement and square-bar specimens with reinforcement were fabricated from the weld-joint. Using the three types of specimens, slow strain rate tensile tests were performed in 0.1 MPa nitrogen gas and in 115 MPa hydrogen gas at a temperature of -40 °C. Reduction of area (RA), φ, for the round base-metal specimen, the round weld-joint specimen and the square weldjoint specimen were respectively, 83.5 %, 71.3 % and 81.4 % in nitrogen gas, whereas the related values in hydrogen gas were 60.1 %, 61.3 % and 40.1 %. In other words, the RA for the three types of specimens was smaller in hydrogen gas than in nitrogen gas. Dimples were formed on the fracture surfaces of the three specimen types in nitrogen gas, whereas both dimples and quasi-cleavages were formed in hydrogen gas.
AB - A case study was conducted on the cooling pipe of a pre-cooler which had been used in a 70-MPa hydrogen station demonstration project. The cooling pipe consisted of a main pipe, a mechanical joint pipe and a mechanical joint. The main and mechanical joint pipes had been joined using TIG welding. Through chemical composition analysis, microstructure observation and Vickers hardness measurement, it was revealed that the main and mechanical joint pipes had been manufactured from SUS316L and that 316L was the filler metal used for TIG welding. Round-bar specimens were machined out of the main pipe in order to investigate the tensile properties of the base metal. On the other hand, both round-bar specimen without reinforcement and square-bar specimens with reinforcement were fabricated from the weld-joint. Using the three types of specimens, slow strain rate tensile tests were performed in 0.1 MPa nitrogen gas and in 115 MPa hydrogen gas at a temperature of -40 °C. Reduction of area (RA), φ, for the round base-metal specimen, the round weld-joint specimen and the square weldjoint specimen were respectively, 83.5 %, 71.3 % and 81.4 % in nitrogen gas, whereas the related values in hydrogen gas were 60.1 %, 61.3 % and 40.1 %. In other words, the RA for the three types of specimens was smaller in hydrogen gas than in nitrogen gas. Dimples were formed on the fracture surfaces of the three specimen types in nitrogen gas, whereas both dimples and quasi-cleavages were formed in hydrogen gas.
UR - http://www.scopus.com/inward/record.url?scp=85034032866&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85034032866&partnerID=8YFLogxK
U2 - 10.1115/PVP2017-65435
DO - 10.1115/PVP2017-65435
M3 - Conference contribution
AN - SCOPUS:85034032866
T3 - American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
BT - Materials and Fabrication
PB - American Society of Mechanical Engineers (ASME)
ER -