Actual hydrogen partial pressure of the base metal in the hydrogenation reactor

How is the hydrogen partial pressure in the base material measured? I’ve never heard of it. The hydrogen content in the base material is related to the quality of the smelting process, as well as to how well the welding is done~

I don’t understand what you mean. Isn’t the hydrogen partial pressure calculated based on the composition of the medium?

Based on the above Nelson curves, it is possible to determine whether the corresponding material has a tendency to suffer from hydrogen corrosion; here, the hydrogen partial pressure refers to that in the medium. It is calculated based on the hydrogen fraction; currently, large petrochemical plants in China such as Zhenhai and Maoming have begun using hydrogen flux meters to monitor the hydrogen content and hydrogen partial pressure online. What the original poster means is that the hydrogen partial pressure within the material refers to those hydrogen bubbles with high internal pressure that are formed either by the escape and accumulation of hydrogen atoms in the steel, or by the infiltration of hydrogen into the material; these bubbles are similar to white spots. This \"hydrogen partial pressure\" is difficult to measure, and its value varies significantly depending on the welding and heat treatment conditions in different parts of the material

:Well, according to what was said upstairs, it seems there might be some hydrogen bubbling.

The hydrogen partial pressure should be provided by the process engineering team.

This post was last edited by realben on 2009-11-5 at 16:34. 5# Wen Bing lists the following as the main problems associated with hydrogenation reactors: (add more if not all are listed) 1. Tempering brittleness of Cr-Mo steel, 2. Hydrogen sulfide stress corrosion, 3. High-temperature hydrogen damage (HTHA). High-temperature hydrogen damage includes hydrogen embrittlement (HE), hydrogen corrosion, hydrogen bulging, and hydrogen-induced cracking (HIC), among others. All are related to the hydrogen partial pressure. The above is purely a personal summary; I’m not sure if it’s appropriate, so please feel free to correct me. Here’s some additional information for everyone:

The hydrogen partial pressure can be roughly estimated using empirical formulas; there is no method for measuring it accurately. The local hydrogen partial pressure in materials can easily exceed the material’s tensile strength, and this is also the main cause of HIC and HB.

Generally speaking, the hydrogen partial pressure refers to that of the operating medium, not that of the base material; it seems impossible to define the hydrogen partial pressure of the base material, let alone measure it. Furthermore, the hydrogen partial pressure has no direct relationship with hydrogen sulfide corrosion.

Main damage modes of hot-wall hydrogenation reactors: high-temperature hydrogen corrosion (surface decarburization, internal decarburization and cracking), hydrogen embrittlement, high-temperature hydrogen sulfide + hydrogen corrosion, temper embrittlement of chromium-molybdenum steel, polyoxysulfate stress corrosion cracking, and hydrogen-induced delamination of the surfacing layer on austenitic stainless steels.

I agree with the opinion on the 4th floor; the hydrogen partial pressure is mainly calculated based on the medium, and this view is correct. How is it measured in steel? Could a friend help?