Читать книгу Root Cause Failure Analysis - Trinath Sahoo - Страница 133

Failure of an engineering component can occur due to abnormal service condition experienced by them for which they are not designed. These abnormal service conditions may appear in the form of exposure of component to excessively high rate of loading, unfavorable oxidative, corrosive, erosive environment at high or low temperature conditions for which it has not been designed. The contribution of any abnormality in service conditions on the failure can only be established after thorough investigation regarding compatibility of the design, manufacturing (such as heat treatment) and material of the failed components with condition experienced by them during the service.

Stress overloads, excessive temperatures(hot or cold), inadequate abnormal corrosive environments, excessive speed, shock, thermal and mechanical, and excessive wear are all common misuse or misoperations that can promote premature and material failures. Loss of metal from corrosion including chemical attack, liquid metal corrosion, stress accelerated corrosion, and corrosion fatigue are common. Inadequate or maintenance such as poor lubrication, weld repairs, contamination, and cold straightening without thermal stress relieving and wear compensation can lead to accelerated wear resulting in deformation that promote fatigue, of rotating or static components.