Online monitoring of structural materials integrity in process industry for I4.0: A focus on material loss through erosion and corrosion sensing

Non-Destructive Diagnostic Methods for Fire-Side Corrosion Risk Assessment of Industrial Scale Boilers, Burning Low Quality Solid Biofuels—A Mini Review

“…Ultrasonographic methods utilize phenomena that result from differences pertaining to the speed of mechanical vibration movement in the materials studied and their surroundings [70,75,76]. The differences trigger the reflection of waves at the media boundaries.…”

“…The MFL method employs the magnetization of the material studied to the saturation level as well as the measurement of magnetic field corona in places in which material losses and other anomalies are located [71,72,75]. Detecting defects by means of this technique has been known for a long time; new studies concerning this issue refer to methods of establishing the structure of detected defects.…”

“…It is possible to apply this approach to other insulated or difficult-to-access test objects, where no contact with the probe is required [81]. Other methods, such as RFID (radio frequency identification) [75], as well as microwave-based sensors [75,84], have attracted interest as novel diagnostic techniques for online monitoring of structural materials' integrity in the process industry, especially in the context of the development of so-called industry 4.0 [75].…”

“…Al-Mayouf and Al-Shalwi [89] investigated a simple galvanic sensor that was useful for determining the start of iron corrosion under situations similar to those used for separating layers of iron oxide magnetite from the steam boiler with the 5% HCL solution at 60 • C. The time at which the inclusion of corrosion inhibitors is needed to safeguard the base metal can be signaled by this sensor [89]. The fiber brag grating (FBG) system employs the use of photoacoustic sensors [75]. With a photoacoustic sensor, two types of ultrasonic waves are generated: body waves (i.e., p-waves and s-waves) and surface waves (fundamental mode of Rayleigh waves), which have higher amplitude and are more sensitive to corrosion [75].…”

“…The fiber brag grating (FBG) system employs the use of photoacoustic sensors [75]. With a photoacoustic sensor, two types of ultrasonic waves are generated: body waves (i.e., p-waves and s-waves) and surface waves (fundamental mode of Rayleigh waves), which have higher amplitude and are more sensitive to corrosion [75]. Recently, PARC Company has developed a technique to allow optical fiber sensors to detect the wavelength deviation with a 50 femtometer resolution [75].…”