Carburization Damage in Heater Tubes
Furnace tubes that are made of high chrome material often will carburize when in hydrocarbon service.
Coker furnaces, found in oil refineries are particularly susceptible to carburization which starts on the inside of the tube. As the material carburizes, it loses ductility and can eventually fail. The carburized material represents virtually no actual wall loss, therefore A-Scan ultrasonics is ineffective at determining caburized thickness.
- The image at right shows a sample of carburized pipe, showing the case depth of the carburization.
- As carburization is difficult or impossible to detect with standard A-Scan ultrasonics, Electromagnetic technique is developed to detect the worst areas.
- The electromagnetic tool can be used to scan the length of the tubes ,this will detect variations in the amount of carburization present.
- Confirmation and sizing of carburization can also be accomplished by the Ultrasonic Technique for internal carburization to accurately measure case depth.
- To confirm and size carburization, specially designed scanners are used, scanning is performed around the tube, across the hot face of the tubes.
At Focus Integrity Solutions we have all the required expertises along with needed equipment to differentiate and distinguish between the different stages of damages. This helps our clients to take decision on repair and replacement of the carburized tubes.
