“Progressive Failures of Components in Chemical Process Industry: Case History Investigation and Root-Cause Analysis”, In Handbook of Materials Failure Analysis with Case Studies from Chemicals, Concrete and Power Industries, Edited by Abdel Salam Hamdy Makhluf and Mahmood Aliofkhazraei, BH-Elsevier 2016, 1-23
Abstract
The increased significance and value of the multi- and interdisciplinary failure analysis field
arises from the benefits incurred in terms of insurance costs, quality improvement and
prevention or minimization of environmental and safety risks. Especially in the chemical
industry sector, the preventive role of failure analysis is of paramount importance, since the
criticality and risk of an unfolding failure event provides a potential of huge safety and/or
environmental hazards (chemical accidents, explosions, environmental-type leakages, etc.).
Progressive-type failures are considered as the most insidious damage mechanisms which
are very often difficult to detect and predict. Aggressive service conditions prevailing in
chemical process plants, such as elevated temperature and pressure, corrosive
environments, etc, stretch the safety operating limits of engineering materials and
components at challenging levels of endurance and reliability. The current chapter presents
the investigation methodology of characteristic failures of chemical and process plants
components, based mainly on case history investigation approach. A brief introduction
addresses the progressive failure modes, focusing mainly on creep and stress corrosion
cracking (SCC) in special steel structural members. Next, the results of the investigation of
two respective case histories are thoroughly analyzed and discussed. The evolution of creep
damage is presented in the case of a steel pipe operating in a power plant together with the
discussion of the influence of operation parameters. The stress corrosion cracking (SCC)
mechanism is addressed through the catastrophic failure of stainless steel screen (grid) used
in a naphtha production unit in petrochemical industry. Visual inspection, optical microscopy
and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Microanalysis
(EDS) were used as the principal analytical techniques for the case history failure
investigation.