Thursday, February 8, 2018

The CIRC E-PIT: Helping Stop Carburization Before it Starts!

pipe carburization

Carburization of furnace tubes is serious issue that impacts refineries, gas plants and other industries worldwide with potential catastrophic consequences. Carburization, or the introduction of carbon into the material of components in high temperature environments (high chrome steel furnace tubes), leads to the hardening of the tubes, making them less ductile and prone to brittle failure. Once damage occurs, repairs can be extremely expensive, and in many cases, replacement becomes the only option.

As a foremost provider of NDE technologies, Russell NDE has developed a tool to aid in the detection of early signs of carburization. The CIRC E-PIT, connected to the Ferroscope 308 uses remote field eddy current technology (RFT) to evaluate the tubing commonly used in furnaces. The probe is able to scan around the tubing, and is held in position with a Velcro strap, making the scanning process very easy for the operator. Internal coils send a signal through the tube, which permeates through the tube wall and down the length of the tube and reflects back to a sensor which provides data for analysis. Typical furnace tube materials such as 9 chrome can be inspected at rapid speed, giving results with a minimal wait period.

metal carburization from outside in

How can you protect against carburization?

As with most forms of corrosion and erosion that are not visible when the component is in service, regular inspection on shutdowns is the proper way of identifying and quantifying it. Being proactive is the only way to circumvent costly repairs or replacements. Russell recommends inspection using E-PIT and CIRC-E-PIT to identify and quantify the extent of carburization; however, it is also important to remove tube samples from different elevations in the furnace to confirm and calibrate the NDT results.

carburizated metal ndt

Want to have your tubes inspected?

We can help! Contact a member of Russell NDE Technologies today to learn more!