Sensitization of Sensitization-Resistant Stainless Steel

Stainless steels are made sensitization-resistant by the addition of stabilizing elements to the alloy. These stabilizers provide a preferential carbide-forming alternative that preserves the chromium, along with its passivation effects on the base material and heat-affected zone of a welded joint. In so doing, the corrosion resistant properties are also preserved. The advantage of the stabilizers, however, can be circumvented under certain welding conditions. We will review a case study that involves such a welded-joint failure, identify candidate adverse welding conditions that might have precipitated the failure, and describe precautions that could have been taken to avoid sensitization of the stainless steel welded joint.