Residual Gas Desorption Rate
The residual gas desorption rate indicates how quickly gases like hydrogen or oxygen are released from the metal structure when temperature rises. A high desorption rate can cause stress in the workpiece and lead to cracks.
Physicochemical mechanism of action
At elevated temperatures, gases such as hydrogen or oxygen dissolve out of the metal structure. These released gases can be converted into stresses that arise in the workpiece.
Metallurgical relevance & risks in welding
A high residual gas desorption rate can lead to increased stresses, especially when the metal is under pressure. This can result in cracks or distortion in the workpiece. This is particularly important in high-pressure connections or with metals having high gas content.
Workshop practice & instructions
To minimize the risks of residual gas desorption, welding should be performed under low stress and pressure. For metals with high gas content, slow cooling is recommended to keep desorption under control. The maximum temperature during welding should be kept as low as possible to reduce the desorption rate.