November 22, 2012

A Magic Formula to Predict Fracture in Steel

EPFL researchers have elucidated a century-old mystery: how hydrogen destroys steels. A new mathematical model predicts this failure in the presence of the destructive atoms.

A veritable gangrene for steels and other structural metals, hydrogen is one of the most important causes of ruptures in industrial parts, such as pipelines. At the slightest defect in a material, these atoms introduce themselves in the crack and weaken the structure dramatically, making it brittle. The material need only be in contact with aggressive substances or placed in an aqueous environment from which for the dangerous hydrogen atoms enter the material. This phenomenon of "hydrogen embrittlement" has been known for many years, but so far no one managed to capture the physical process or predict when hydrogen embrittlement will occur. Bill Curtin of the Laboratory of Multiscale Mechanical Modeling at EPFL and his collaborator Prof. Jun Song at McGill, tackled this problem and developed a mathematical model to understand the behavior of hydrogen atoms in iron-based steels and thus to predict steel fracture. This is revolutionary in the world of materials, and serves as the subject of an article in the journal Nature Materials.