Copper "hydrogen disease" refers to ordinary copper, in the reducing atmosphere containing hydrogen or carbon monoxide when heated, hydrogen or carbon monoxide and grain boundaries of cuprous oxide (Cu₂O) reaction, resulting in high-pressure water vapor or carbon dioxide gas, so that the copper rupture phenomenon.
Specific performance are: produce internal defects produced by the reaction of water vapor insoluble in copper, along the grain boundaries overflow, so that between the grain expansion cracks. Upon cooling, these swelling cracks will exist in the form of voids on the grain boundaries. Surface anomalies can be seen on the surface of the copper protruding small bubbles, seriously affecting the appearance of the quality of copper products. Reduced Mechanical Properties "Hydrogen Disease" causes copper to become brittle and weakened, resulting in chronic air leakage and making it unsuitable for applications that require high levels of airtightness and strength. In general, the solubility of hydrogen in liquid and solid copper increases with temperature. Hydrogen sickness" can be caused by the presence of hydrogen in the environment or conditions that produce hydrogen during copper melting and processing. In order to avoid the occurrence of "hydrogen disease", pure copper can not be annealed, brazed or sealed in hydrogen, and needs to be heat-treated in a vacuum. Oxygen-free copper with low oxygen content, heat treatment in hydrogen is not easy to occur "hydrogen disease" ...... How to prevent copper "hydrogen disease"? Good control of environmental factors, atmosphere control. In the copper processing, heat treatment and other processes, strict control of the atmosphere environment. For example, in the annealing, brazing and other processes, the use of vacuum or inert gas (such as nitrogen, argon) protection, to avoid copper and hydrogen or carbon monoxide-containing reducing atmosphere contact. For some processes that must be carried out in a specific atmosphere, the hydrogen content can be reduced by purifying the atmosphere. For example, gas purification devices are used to remove moisture and hydrogen-containing compounds from the atmosphere. Storage and transportation environment. During the storage and transportation of copper products, it is also important to pay attention to the control of the environment. Avoid placing copper products in humid, hydrogen-containing environments. Sealed packaging, desiccant and other measures can be used to keep the storage environment dry. For copper products stored for a long period of time, regular inspections and maintenance should be carried out to detect and deal with possible signs of "hydrogen disease" in a timely manner. Selection and treatment of materials Select suitable copper materials, giving priority to oxygen-free copper or high-purity copper. Oxygen-free copper has a low oxygen content and is less prone to "hydrogenosis" when heat-treated in hydrogen. High purity copper is also less prone to hydrogenosis due to its low impurity content. For applications that are particularly sensitive to hydrogen sickness, special copper alloys can be selected, which have been specially treated or have specific elements added to them to increase their resistance to hydrogen sickness. In addition, copper products can be surface treated to remove the copper oxide layer on the surface. Mechanical polishing, chemical pickling and other methods can be used to keep the copper surface clean and smooth, reducing the possibility of reaction with hydrogen or carbon monoxide. It is also possible to coat the copper surface with a protective film, such as organic coatings, metal plating and so on. These protective films can prevent the penetration of hydrogen and also play a role in corrosion prevention.
Optimization of the process Control of processing temperature and time. In the copper processing process, the heating temperature and time are reasonably controlled. Avoid too high a temperature and too long a heating time to reduce the dissolution and diffusion of hydrogen in copper. For processes that require multiple heating, pay attention to controlling the number of heating times and intervals to minimize the accumulation of hydrogen. Cooling rate control. In copper casting, heat treatment and other processes, control the cooling rate. Slow cooling allows the hydrogen dissolved in the copper to have enough time to diffuse into the external environment, reducing the risk of "hydrogen disease". Segmented cooling, control of the cooling medium and other methods can be used to optimize the cooling process and improve the quality of copper products.
