Causes and Preventive Measures of Interlayer Crystallization Cracks and Surface Liquefaction Cracks During TP321 Welding Process
Due to the special environment of high temperature,high pressure and hydrogen in hydrogenation unit,the pipelines at the inlet and outlet of the heater,reactor and high-pressure heat exchanger have to be made of TP321 or TP347.However,in the process of device construction,due to tight construction period,poor welding environment,uneven level of welders,poor welding material composition and weldability,and harsh control of heat input and interlayer temperature,welding quality problems such as hot cracks occur in the welding process.In order to ensure the welding quality of TP321 pipes,the causes of the above quality problems were briefly described to ensure proper heat input during the welding process,the application of qualified welding materials,and the ferrite content of the weld structure,so as to ensure the safety and stability of the pressure test,startup and shutdown process of the device.
Hydrogenation deviceTP321Interlayer crystallization cracksSurface liquefaction cracksFerriteLow temperature cocrystal