Intergranular corrosion of a stud used in safety relief valve

In the present paper, a failure case study on intergranular corrosion of stainless steel stud is discussed. The stud was in the assembly under marine environment, for a period of 11 years. Detailed investigation revealed that the crack had propagated in an intergranular manner, after initiation at threaded region of the stud, leaving behind widespread grain dissolution. The presence of chloride ions in deposits on central region of stud, exposed to marine environment was also established. The high carbon content, coupled with exposure to sensitization range of stainless steel during processing caused corrosion along intergranular corrosion.This paper brings out the details of investigation carried out on the failed stud.