Session: CS-10-01 Recent Developments in Chinese Codes and Standards-1

Paper Number: 154322

154322 - Research on the Mechanical Behavior of Commonly Used Steels for Pressure Vessels and Pipelines in China Under Ambient Temperature and High-Pressure Hydrogen Environment 

Abstract: 

  Hydrogen gas is one of the important long-term energy storage methods for renewable energy, and hydrogen utilization is also considered as an important means of achieving carbon reduction. At present, hydrogen storage and transportation under ambient-temperature and high-pressure is an important method for hydrogen energy storage and transportation. However, due to the threat of hydrogen embrittlement under high-temperature high-pressure environment, there is a common concern over the hydrogen embrittlement of the steel pressure vessels and pipelines caused by hydrogen, which may result in unsafe consequences.

  In the present paper, the hydrogen charging tests, the slow strain rate tensile (SSRT) tests and the hydrogen-induced cracking tests with the wedge-open loading (WOL) samples under ambient-temperature high-pressure gaseous hydrogen environments were carried out for the commonly used pressure vessel steels Q345R, 30CrMo, and X80 pipeline steel in China. The experimental results show that hydrogen hardly penetrates into Q345R, 30CrMo and X80 steels under ambient-temperature and 35 MPa gaseous hydrogen environment. When the hydrogen pressure increases to 70MPa, it is also difficult for hydrogen to penetrate the above three kinds of steels, and the maximum increase in hydrogen concentration is only about 0.1 ppm. When the hydrogen pressure increases up to 110MPa, a small amount of hydrogen can penetrate 30CrMo steel (the increase in hydrogen concentration is 0.38ppm), but it is still difficult for hydrogen to penetrate Q345R and X80 steels (the increase in hydrogen concentration is less than 0.04ppm). The SSRT tests under the ambient-temperature and 35 MPa gaseous hydrogen environment show that the elongation (EL) and reduction of area (RoA) of the above three kinds of steels does not significantly decrease. Compared with the SSRT results under the ambient-temperature and 35 MPa gaseous nitrogen environment, the ELs of Q345R, 30CrMo, and X80 steels decrease by 0.2%, 4.3%, and 3.2%, respectively. The RoAs of Q345R, 30CrMo, and X80 steels decrease by 0.4%, 8.4%, and 1.5%, respectively. In addition, the results of the hydrogen-induced cracking tests with WOL samples show that, even if the applied stress intensity factor reaches 103 MPa·m^1/2, the pre-crack of 30CrMo steel does not propagate under the ambient-temperature and 110 MPa gaseous hydrogen environment.

  Overall, hydrogen has almost no effect on Q345R, 30CrMo and X80 steels under the ambient-temperature and medium-high pressure (below 35MPa) gaseous hydrogen environment. When hydrogen pressure reaches 70MPa, there is little difference in hydrogen permeation compared to the 35MPa condition, so its impact on their mechanical properties could be small as well. When the hydrogen pressure reaches 110MPa, the 30CrMo steel with the highest hydrogen permeation also exhibits good resistance to hydrogen induced cracking, indicating that hydrogen has limited influence on the mechanical properties of the steels.

Presenting Author: Xuedong Chen Hefei General Machinery Research Institute Co. Ltd. (HGMRI)

Presenting Author Biography: Prof. Xuedong Chen is Member of Chinese Academy of Engineering, Director of National Technical Research Center on Safety Engineering of Pressure Vessels and Pipelines, and Chair of China International Working Group (CIWG) for ASME BPVC-VIII. He has been engaged in the research and application of pressure vessel and pipeline safety science and engineering technology for more than three decades.

Authors:

Xuedong Chen Hefei General Machinery Research Institute Co. Ltd. (HGMRI)
Zhichao Fan Hefei General Machinery Research Institute Co., Ltd.
Yu Zhou Hefei General Machinery Research Institute Co., Ltd.
Hao Yang Hefei General Machinery Research Institute Co., Ltd.
Qiang Zhang Hefei General Machinery Research Institute Co., Ltd.