Welcome to SMPES LLC's Failure Analysis Page

Many aspects of engineering and analysis tools are required to answer our question of why did it fail. This page aims at providing a basic understanding of what a metallurgical or physical failure analysis looks for in predicting what caused the failure. Light microscopy and scanning electron microscopy are two of the primary analysis tools available. Compositional analysis techniques, such as energy dispersive spectrometer, are another significant tool.  

Descriptions and images have been provided for seven categories of failure types.  Please bookmark our site as we will continue to add content, useful information and links to this site.

Lab Services

SMPES, LLC has teamed up with Scientific Testing Laboratories to provide you with the necessary physical laboratory testing for your failure analysis, welder and weld procedure qualifications, and field services needs.  

Case Study - Electron Mapping of Heater Tube

Electron mapping, using an environmental electron microscope, was performed for a client who had a cracked heater tube.  The tube is located outside the furnace and is subject to ambient conditions for long periods of time as this is a start-up heater.  EDS which provides a gross analysis showed the sulfur content at 0.30% at the tube OD, where 0.03% is the typical maximum allowable.  The tube ID did not show an unusual amount of sulfur.  Electron mapping of the crack tip proved that the grain boundaries had a very high sulfur content (nearly 7%).  Light microscopy and SEM work showed the crack to be intergranular. Thus, it was concluded that sulfur in the atmosphere from the neighboring fertilizer plant, mixed with condensation during the down times of the startup heater, thereby causing polythionic acid corrosion cracking.  Images above show the location of electron mapping and electron mapping results.  Sulfur is relfected by the bright fluorescent blue color.