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.