Hydrogen embrittlement of austenite

By H. K. D. H. Bhadeshia September 2026

1. Introduction

A publication (Yu, Luo, Zhao, Sun, Liu, Qin, Wang, Li, Corrosion Science. 2026, 28, 114211) investigates hydrogen embrittlement of additively manufactured austenitic stainless steel.

The use of the term hydrogen embrittlement is unjustified. In one case, the elongation in a tensile test decreased from 50.6 to 49.6%, and in another from 51.1 to 46.2%, with a reported uncertainty of up to ±2%. In other words, grossly ductile fracture absorbing many orders of magnitude more energy than cleavage fracture.

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2. Mechanism

The authors go on to interpret their results in terms of the infamous hydrogen enhanced local plasticity theory of embrittlement. At least five slip systems must operate in each grain in order to account for the observed gross ductility. The hydrogen enhanced local plasticity model relies on slip localised on a particular plane.

Reference

  1. H. K. D. H. Bhadeshia: 'Karl Popper and the theories of hydrogen embrittlement': Advanced Engineering Materials (2026) e202503067.