Failure Investigation of High Temperature Stud

摘要

The premature failure in a high-temperature stud is investigated in this article. The visual examination, dimensional measurement, and wet fluorescent magnetic particle, and chemical compositions are carried out as part of preliminary investigation. Apart from these tests, microstructural examination, tensile, impact and fractographic analyses are also conducted as part of the investigation. Finally, it has been concluded that the failure of the stud is caused because of the presence of severe localized, elongated, and oriented inclusions along the thread profile, particularly near the thread-root region. The inclusions may act as stress inducers under service load and facilitate initiation of cracks. The cracks are further propagated, finally leading to premature failure of the stud.