Zircaloy-4 stress corrosion by iodine: identification of critical parameters influencing cracking stages

The authors report an investigation the aim of which was to identify the critical parameters involved in the appearance of a transgranular crack propagation in fuel pins in Zircaloy 4 alloy subjected to stress corrosion by iodine. Zircaloy 4 specimens (cold worked or not) have been submitted to a constant load in presence of iodized methanol. Fracture surfaces are analysed by scanning electronic microscopy. Transmission electronic microscopy is used for matters of result interpretation and microstructure comparison, notably for intergranular and transgranular cracking zones after corrosion stress cracking test