Testing and mesoscale modelling of hydrogen assisted cracking of magnesium

To rationalise the results of stress corrosion cracking tests on smooth tensile specimens of a magnesium alloy, performed as constant extension rate tensile tests, a mesoscale fibre bundle model is employed in which the material being tested is represented by a bundle of parallel fibres. The effect of hydrogen embrittlement on the stress–strain curves measured at various strain rates is simulated by assuming that the hydrogen is generated in localised corrosion pits and subsequently diffuses into the bulk, thereby reducing the strain-to-failure of individual fibres. The stress–strain curves obtained from these simulations show the same strain rate effect as was experimentally observed.