Decarburization is reduction of carbon content in the surface when steel heated. The process of decarburization is carbon in steel produce methane or carbon monoxide with hydrogen or oxygen at high temperature.
After austenitic decarburization, the surface of the tubing will not form uniform austenite. Not only the strengthen of cold deformation is not up to the requirements, but also crack generation by inhomogeneous deformation.Different tissues will cause a lot of stress when quenching and the strength of surface will decline after decarburization. Even in the quenching process, sometimes it cause crack on the surface.