Effect of grain boundary orientation on the sensitization of austenitic stainless steel

The effect of grain misorientation on the sensitization of grain boundaries in austenitic stainless steel was investigated by sensitizing samples consisting of a large number of 50–80 μm size grains that were sintered to flat, 10 mm2 single crystals. Seven different sensitization treatments were employed and samples were intergranulary corroded in the modified Strauss test. X-ray pole figures were obtained for each sample and were used to identify the grain misorientations that were resistant to sensitization. In general, macroscopic grain boundary geometry could not explain the sensitization behaviour of most grain boundaries. Nevertheless, the Σ = 9 boundary was found to be especially resistant to sensitization. Results suggest that grain misorientation primarily affects the growth of sensitization rather than its nucleation. Finally, the crystallographic plane of the grain boundary appears to have an effect on sensitization. This revised version was published online in November 2006 with corrections to the Cover Date.