Page 35 - Handbook of Materials Failure Analysis

28 CHAPTER 2 Failure analysis in chemical industries

dissolution of microstructural phases, biologically influenced corrosion, localized
attack by the species in the environment, erosion, gouging, cavitation, chemical
attack, etc. In addition to the techniques used for metallurgical failure analysis,
the electrochemical testing for predicting behavior of same material in simulated
environments could also be beneficial to define mechanism. The accurate prognosis
to define failure cause needs an expert and a conceptual approach. An analyst can
trace back to the product history by closely looking at one or more factors involved
in its lifecycle which could also disclose any likelihood of premature failure.
The findings of failure analysis and knowledge of prior damages can be useful
in the designing of reliable products, modifications in the manufacturing processes,
and developing safe operating procedures. Furthermore, the analysis reports could
be beneficial for a materials engineer to identify deficiencies in the existing structural
materials, provide guidance to look at alternate materials, and/or improve the prop-
erties. The equipment in a chemical process industry during operation experiences
extended thermal and intensive pressure cycles which could lead to deterioration
of materials. The complex nature of stresses and adverse environmental factors could
induce deleterious corrosion effects on the performance of engineering materials and
hinder the continuity of operations.
It has been shown in Figure 2.2 that major contributors to accidents in the past
were human errors, process control, manufacturing/installation, materials selection,

8.1 1.8
16.2
7.4
7.4

9.5

38.7
10.9

Human/organizational errors Process control defficiencies
Design Manufacturing and installations
Material selection Corrosion
Unexpected Others
FIGURE 2.2
Major factors that contributed to failures in chemical process industries.
Data extracted from table 2 of Ref. [5].