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Many a times unanticipated equipment failures do occur for a variety of reasons. These events often become too costly as well as disruptive to plant operations and may also have safety implications. To minimize the frequency and severity of such failures, it is necessary for personnel who have equipment responsibility to understand the failures and to confront their causes. Potential causes of the failure of the components and their mechanism are numerous. Therefore, procedure of the failure analysis of each failed component should be different and the same must be developed after giving proper thought on possible sequence of events before failure along with proper evaluation of the situation and consideration of material, manufacturing process, service history and actual working condition, etc. Since the failure analysis involves lot of efforts, time and use of resources therefore at the end of analysis failure analyst should be in a position to come out with few most potential causes of the failure so that suitable recommendations can be made to avoid reoccurrence of the similar failure.

It may sound a little far‐fetched, but experts say that the causes for more than 90% of all plant failures can be detected with a careful physical examination using low power magnification and some basic physical testing. Inspection of the failure component will show the forces involved, whether the load applied cyclically or was single overload, the direction of the critical load, and the influence of outside forces such as residual stresses or corrosion. Then, accurately knowing the physical roots of the failure, you can pursue both the human errors and the latent causes of these physical roots.

In this chapter, an overview of the processes involved in a typical metallurgical failure analysis is provided. The discussion describes various failure mechanisms in metals that can be examined, some of the tests and processes that are used in an analysis, for failed components.

The metallurgical failure analysis can be defined as a scientifically based systematic laboratory examination of metallurgical evidence and the gathering of background information related to an equipment failure. This analysis helps in establishing the cause of the failure. Because the approach to the failure analysis is usually determined by the nature of the failure, all analyses do not require the same procedure. Laboratory procedures focus on the failed equipment itself and most commonly consist of general and detailed macrophotography, metallo‐graphic examination, chemical analysis of the failed part and of any extraneous or foreign materials present, mechanical property determinations, fractographic examination, and others.