Stainless steel alloy hydrogen stripping test
Hydrogen stripping test, hydrogen stripping detection mechanism
Tianjin Rong Da Testing Co., Ltd. contact: Wang Jingfu
Cell phone: 13102238283 QQ:3144667033
Telephone: 022-23892103
After a certain period of time, the hot wall hydrogenation reactor is used to detect the phenomenon of the separation of the main part of the surfacing layer, which is called the hydrogen stripping of the surfacing layer.
The reason for hydrogen stripping is that the current consensus is that:
1 reactor body material and surfacing layer has different hydrogen solubility and diffusion rate, which leads to the high hydrogen concentration in the surfacing layer;
2 because of the difference of the thermal expansion coefficient between the substrate and the surfacing layer, the large residual stress is generated at the interface;
3 metallurgical factors at the interface of the surfacing layer. The reactor at the interface between substrate and cladding layer peeling phenomenon, is also a kind of essence of hydrogen embrittlement.
Causes of peeling occurs, the more consistent view is: the operation of the absorbed hydrogen at high temperature and high pressure in the shutdown cooling process will accumulate in the substrate and the cladding layer interface (coarse microstructure of the interface and the associated part of sigma phase or martensite), higher hydrogen concentration. In addition, the thermal expansion coefficient of the substrate and the surfacing layer is large, and the thermal stress is relatively large. The combined action of hydrogen and stress is easily induced by stripping. The reactor at the interface between substrate and cladding layer peeling phenomenon, is also a kind of essence of hydrogen embrittlement (hydrogen induced cracking), macro is development along the grain boundary layer, belonging to two different materials in the grain boundary due to residual hydrogen caused by hydrogen embrittlement cracking. There are many factors that affect the anti stripping performance, and many of the mechanisms are still being explored. Therefore, the experimental research is a key direction at home and abroad.