Finite element investigation of IGSCC-prone zone in AISI 304L multipass groove welds

AISI 304L stainless steel is most commonly used for spent nuclear fuel management; however, the welded joints of this steel are susceptible to intergranular stress corrosion cracking (IGSCC) under the influence of low-temperature sensitization. In the present research, the temperature history of two different groove designs (conventional and narrow groove) has been analyzed to ascertain the propensity of the weld zone to intergranular corrosion (IGC). 3D finite element models (FEMs) have been developed to retrieve the nodal thermal history and predict the region susceptible to IGSCC. The FEM results predicted a lower duration of exposure to the IGC temperature range for narrow groove design as compared to conventional design. The lower duration of exposure exhibits a lower propensity to chromium carbide precipitation and the tendency to IGSCC. The FEM analysis also has been used to observe the difference in the size of the region susceptible to IGSCC in the heat-affected zone of the respective weld designs. The predicted results obtained from the numerical analysis were validated by comparing the chromium carbide precipitation for both the groove designs.