Effect of residual strain on radiation induced segregation in SS 304

The effect of residual strain on radiation-induced segregation in proton-irradiated type 304 stainless steel was investigated using electrochemical potentiokinetic reactivation (EPR) test followed by atomic force microscopic examination. The specimens were irradiated to 0.43 and 0.86 dpa. Microstructural observation after EPR of irradiated specimens showed negligible attack on grain boundaries. Attacked linear features were noticed after EPR testing of irradiated specimens while such features were not observed for un-irradiated as-received or irradiated solution-annealed specimen. The presence of linear features after EPR testing of irradiated specimens was attributed to decoration of strain-regions within the matrix by point-defects generated due to irradiation.

Research highlights
► Effect of strain RIS in proton-irradiated SS 304 studied using EPR followed by AFM.
► Residual strain within grains reduced Cr depletion at grain boundaries due to RIS.
► Attack during EPR of irradiated SS 304 observed on linear features within grains.
► Strain-regions within grains decorated by point defects & appeared as linear features.