On the suitability of single-edge notch tension (SENT) testing for assessing hydrogen-assisted cracking susceptibility

TL;DR

This study evaluates the effectiveness of SENT testing combined with modeling to assess hydrogen embrittlement in steel, providing insights into hydrogen interactions and test optimization.

Contribution

It integrates experimental SENT tests with phase-field modeling to accurately predict hydrogen-assisted cracking thresholds and analyze test suitability.

Findings

SENT tests accurately predict hydrogen embrittlement thresholds in steel.

Model simulations align well with experimental results.

Optimal SENT test conditions depend on hydrogen diffusion and stress regimes.

Abstract

Combined experiments and computational modelling are used to increase understanding of the suitability of the Single-Edge Notch Tension (SENT) test for assessing hydrogen embrittlement susceptibility. The SENT tests were designed to provide the mode I threshold stress intensity factor ($K_{\text{th}}$) for hydrogen-assisted cracking of a C110 steel in two corrosive environments. These were accompanied by hydrogen permeation experiments to relate the environments to the absorbed hydrogen concentrations. A coupled phase-field-based deformation-diffusion-fracture model is then employed to simulate the SENT tests, predicting $K_{\text{th}}$ in good agreement with the experimental results and providing insights into the hydrogen absorption-diffusion-cracking interactions. The suitability of SENT testing and its optimal characteristics (e.g., test duration) are discussed in terms of the various simultaneous active time-dependent phenomena, triaxiality dependencies, and regimes of hydrogen embrittlement susceptibility.