Decarburization is the loss of carbon in steel, which can be intentional or a result of corrosion. It weakens the metal and can cause cracking. Testing can determine the level of carbon loss and protective coatings or controlled oxygen flow can prevent it. Material testing can also identify decarburization as a cause of steel component failure.
Decarburization is a change in the structure and content of steel in which some of the carbon in the surface layer or layers of the steel is lost. In total decarburization, the top layer of the steel is composed mainly of ferritic materials, while in partial decarburization, a mixture of materials may be present. Microscopy can be used to identify carbon loss, and other testing techniques are also available.
In some cases, decarburization may be done deliberately. In other cases, it’s a byproduct of corrosion or poor handling techniques. Classically, decarburization occurs when steel is heated in an oxygen-containing environment, leading to oxidation and loss of carbon. As a result of decarburization, the metal loses some of its strength and ductility and can develop cracks that make it vulnerable to cracking. The surface of the steel can also become scaly.
When decarburization is considered a defect, material tests on the steel are used to confirm that the level of carbon loss is acceptable. Otherwise, steel will not be used. Carbon loss can make structural steel less stable, erode the performance of steel tools, and cause a variety of other problems with steel equipment. In some settings where it is deliberately desired, tests can also be used to determine what level of decarbing has been achieved.
The rate of decarburization can be controlled. If not desired, protective coatings can be used on the steel to prevent corrosion, or it can be heated in an inert oxygen-free atmosphere. A number of systems for controlling carbon loss are available through companies that manufacture equipment used in steel fabrication and machining, and it is also possible to develop a custom system for a specific need. Conversely, the flow of oxygen into a furnace can be controlled to achieve a desired level of carbon loss.
When steel components fail, such as when a bridge collapses, material testing can be used to learn more about the steel and to identify any problems that may have contributed to the failure. Decarburization can be involved in the failure of steel components and leaves behind a clear trail that makes it hard to miss. In the process of identifying the cause of a problem, inspectors may also be able to determine who is responsible. For example, a construction company may have used substandard steel to cut costs.
Protect your devices with Threat Protection by NordVPN
