Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 15, 2021 - September 17, 2021
Until now, the strength evaluation of polymer materials used in high-pressure hydrogen has been limited to tests in the atmosphere after exposure to high-pressure hydrogen gas and tests in hydraulic pressure. However, the strength evaluation of polymer materials used in high-pressure hydrogen is limited to tests in the atmosphere and tests in hydraulic pressure after exposure to high-pressure hydrogen gas. On the other hand, Kobelco Research Institute has succeeded in acquiring the strength characteristics of polymer materials with high accuracy in high-pressure gas environment under 90 MPa by using the "material test equipment in the high-pressure hydrogen gas environment". As the test material, polypropylene was injection-molded into an ASTM D1822 Type L tensile impact test piece. The test was performed at room temperature and hydrogen gas pressure under 90 MPa. After pressurization, the mixture was left to stand for 3 days and tested at a test speed of 1 mm / min. Due to the limitation of the stroke of the testing machine, the maximum displacement was set to 40 mm. For comparison, a test was immediately carried out after pressurizing up to 90 MPa nitrogen gas and a test in the atmosphere, respectively. As a result, the yield stress and the flat stress after the yield point were higher under the 90 MPa nitrogen condition than in the atmosphere condition. On the other hand, under the 90 MPa hydrogen condition, the yield stress was lower than the 90 MPa nitrogen condition, and the flat stress after the yield point was about the same level compared to the 90 MPa nitrogen condition.
