254th IISS (Webinar)
June 5, 2024

Digital Transformation Approach to Hydrogen Embrittlement*Hisao Matsunaga1

1

Department of Mechanical Engineering, Kyushu University, Japanmatsunaga.hisao.964@m.kyushu-u.ac.jp
Keywords: Digital transformation, Hydrogen embrittlement*The development of technologies for the safe production, storage, transportation, and utilization of hydrogenis crucial for the realization of a Hydrogen Society, where hydrogen is widely used in daily life, transportation,and industrial activities. Unlike other gases, hydrogen can cause the degradation of metallic materials through aprocess known as hydrogen embrittlement, which includes hydrogen-induced cracking and hydrogen-assistedfracture. The effects of hydrogen atoms on materials have been a subject of significant interest and research in
the fields of materials science and engineering for the past 150 years. Due to the potential for catastrophic
failures in critical structures and components, understanding and mitigating this insidious and often
unpredictable process has become a crucial research area, particularly in the high-pressure hydrogen gas
equipment sector, attracting numerous studies worldwide.
In recent years, there has been an increasing trend of utilizing digital transformation approaches to expedite
research in various engineering fields. This is also true for the evaluation of materials strength. In this context,
the presenter is involved in the Research Initiative of Structural Materials for Extreme Environments (RISME) at
Tohoku University. The presenter’s work focuses on developing a novel evaluation method for thehydrogen-embrittlement properties of steels, leveraging applied statistics and image analysis (Fig. 1). This
research collaboration involves multiple disciplines, including data science, numerical simulation, material
development, and strength evaluation.
During the presentation, the background of the research activity will be introduced, followed by thepresentation of interesting findings and outcomes.

Hydrogenpressure

Chemicalcomposition
LoadingconditionHeat
treatment
Microstructure
image
Linking hydrogen
resistance andMicrostructure

Machinelearning

Prediction ofdominantfactors by
Bayesiananalysis

Crack-growth rate
da/dN

Yieldstress“Gray box”

Output:Fatigue crack-growth property

Input:
Material information and service condition

Utilization for thedetermination ofhydrogencompatibility

Acceleration
rate, fIn air

Application to thedevelopment ofnovel
microstructure

SIF range, ΔK

da/dN = C (ΔK)m • f (ΔK)
f = A [ tanh {B (log ΔK − log ΔKTR) +1} ]1/2

Cross-hierarchicalunderstanding of hydrogenembrittlement mechanism
Database for fatigue
crack growth property
in H2 (Data mining)

Microscopic fracture process

Microstructure
database

Reliability assurance of prediction:
Correspondence between mechanismand prediction

HELP
Elementary process (Atomic simulation)

HESIV

HEDE

Fundamental mechanisms

Fig. 1 Prediction system for fatigue crack growth properties in hydrogen gas.
Acknowledgement
This work was supported by MEXT Program: Data Creation and Utilization Type Material Research andDevelopment Project (Research Initiative of Structural Materials for Extreme Environment).