Investigation of Local Hydrogen Distribution Around Fatigue Crack Tip of a Type 304 Stainless Steel with Secondary Ion Mass Spectrometry and Hydrogen Micro-Print Technique

Abstract

In order to establish an appropriate method for measuring the local hydrogen content distribution around a fatigue crack tip in austenitic stainless steels, secondary ion mass spectrometry (SIMS) and the hydrogen micro-print technique (HMPT) were applied to a fatigue crack in a type 304 stainless steel fatigued in a hydrogen gas environment. The main results in this study are as follows. In the SIMS method, it is visualized that a high content of hydrogen exists in the plastic zone at a fatigue crack tip propagated in hydrogen gas, compared to that on a smooth area fatigued in hydrogen, though there is a measurement error based on false detection due to the edge effect regarding hydrogen in water vapor on the fatigue crack surface. On the other hand, hydrogen in the plastic zone is difficult to detect by HMPT. This is attributed to the difficulty for hydrogen atoms to be emitted from the sample in this case. To detect hydrogen, it is necessary to sputter the atoms forcibly. In addition, it is considered that to analyze the local hydrogen distribution around a fatigue crack tip with SIMS not only qualitatively but also quantitatively, reduction of the false detection due to the edge effect is necessary.

Analysis of Hydrogen Distribution and Diffusion in Pre-Strained SUS316L through Scanning Kelvin Probe Force Microscopy and Thermal Desorption Spectroscopy

“…Their research findings indicated that hydrogen tends to segregate at grain boundaries, leading to an increased likelihood of intergranular fracture. Unfortunately, SIMS is prone to signal interference from the surrounding environment [17,18]. Over the past few years, scanning Kelvin probe force microscopy (SKPFM) has gained recognition as an effective and non-invasive technique for highresolution mapping of localized hydrogen distribution [19].…”

Prediction of crack propagation under cyclic loading based on hydrogen diffusion

“…Hydrogen embrittlement has been well accepted as one of the most severe steel degradation mechanisms [1][2][3][4]. There are several theories to illustrate hydrogen embrittlement in steel.…”

Numerical models for simulating hydrogen diffusion and embrittlement in high strength steels

“…Chapter 2. Review on hydrogen diffusion modelling Ion Mass Spectrometry (SIMS) (Brass, Chene, & Boutry-Forveille, 1996;Mao & Li, 1998) and Micro-Print Technique (Kawamoto et al, 2009).…”