Page 39 - Handbook of Materials Failure Analysis

32 CHAPTER 2 Failure analysis in chemical industries

protocols for analyzing failed components are included but not limited to the follow-
ing steps [34–36]:

• Review of background information related to manufacturing, design
specifications, process conditions, and scheduled maintenance records
• Primary visual or non-destructive testing to evaluate surface or bulk
discontinuities
• Chemical analysis of material, corrosion product, and assembled components
• Monitoring of possible environmental factors which could induce deleterious
effect on material characteristics, that is, electrochemical, mechanical, and
physical, etc.
• Identifying, selecting, and preserving components in order to avoid damage of
surface features which could obstruct correct interpretation of failure mechanism
• Conducting standard metallographic examination to determine microstructural
inhomogeneities and comparison of sound part microstructures with infected one
• Mechanical testing of failed and exactly same material for comparison
• Stress and design analysis of component on the basis of testing results
• Fractography of fractured surfaces to correlate features with microstructural,
stress distribution, and validation of environmental attack
• Electrochemical analysis of failed and unused material in simulated environment
to inquire about any deviation

2.5 COMPILING THE DATA
The analysis and compilation of data is as important as the preliminary steps of fail-
ure analysis. The sequential arrangement of data is important to understand the cause
and mechanism of failure. The presentation of observations and testing results should
be simple and elaborative. There should be a connection between each step of anal-
ysis and representation of the data. The effective and useful way of reporting the
investigation is to convert important data in graphical trends, tables, histograms,
and images. The drawings should be constructed to depict the design of component,
identifying failure zone, and section of samples analyzed. The report language
should be more focused and technical. Keeping in view the importance of failure
investigation, the contents should be arranged in such a way that it can be understand-
able to designer, manufacturer, and user. This document will also be a guide for all of
them to select proper material, treatments, and design to avoid such misfortune in
future.

2.6 DRAWING CONCLUSION
The collection of relevant background data, field inspection, and conduction of lab-
oratory testing are the critical steps for evaluating failure cause. A thorough back-
ground knowledge of equipment or device failed, connecting parts, effect of
operating conditions, material behavior, previous history, maintenance or repair