Metal corrosion analysis is an important tool in preventing corrosion. Metal corrosion is a process by which metals deteriorate because of chemical and/or electrochemical reaction with their environment. Corrosion prevention can be an issue of health and safety. Metal parts make a variety of structures, including bridges and buildings. According to The American Galvanizers Association (AGA), there are several types of corrosion:
- Galvanic
- Pitting
- Microbial
- High temperature
- Crevice
THE PROBLEM: A stainless steel panel was showing discoloration and pitting that suggested it had gone through a corrosion process. Our client requested that we confirm the discoloration was due to corrosion and identify the cause of the corrosion.
THE ANALYSES: Visual inspection of the panel indicated widespread pitting and corrosion (Figure 1). A portion of the panel was cut and analyzed using a scanning electron microscope (Figure 2). The analysis indicated chromium and iron are the base metals of the alloy, and there was abundant chlorine present.
Figure 1 shows an optical image of the pitting. Figure 2 shows an electron image of a pit with corrosions.