Study of grain boundary character along intergranular stress corrosion crack paths in austenitic alloys

Samples of austenitic stainless alloys were examined by means of scanning a nd transmission electron microscopy. Misorientations were measured by elect ron backscattered diffraction. Grain boundary distributions were analyzed w ith special emphasis on the grain boundary character along intergranular st ress corrosion cracks and at crack arrest points. It was established that o nly coherent twin Sigma3 boundaries could be considered as "special" ones w ith regard to crack resistance. However, it is possible that twin interacti ons with random grain boundaries may inhibit crack propagation. The results suggest that other factors besides geometrical ones play an important role in the intergranular stress corrosion cracking of commercial alloys. (C) 2 001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights rese rved.