Intergranular corrosion of welds in type 405 stainless steel

A low chromium ferritic stainless steel (Type 405) with different heat treatments and weld configurations, has been investigated for susceptibility to intergranular corrosion by chemical and electrochemical potentiodynamic reactivation (EPR) tests, and the results were evaluated by weight losses, dye penetration, metallographic techniques, and the ratio of the reactivating and activating currents. Welds are susceptible to attack, particularly in the heat-affected zone. Applied stress in a U-bend increases significantly the attack on welds, and annealing eliminates the effects of stress. Results on the susceptibility of unwelded specimens in the form of flat plates and U-bends after various heat treatments are also presented and discussed.