Heat treatment sharing and supplements:
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0240550093.jpg Based on the purpose of heat treatment, it can be divided into four categories: stress-relief heat treatment, heat treatment to restore mechanical properties, heat treatment to improve mechanical properties, and degassing treatment. The purpose of post-weld stress-relief heat treatment is to improve the microstructure and properties of the welded joint and to eliminate welding residual stresses. The purpose of heat treatment to restore mechanical properties is to recover the plasticity and toughness reduced due to work hardening, thereby ensuring the quality and safety of pressure vessels. Heat treatment to improve mechanical properties, as the name implies, is the use of heat treatment to enhance the mechanical properties of steel. Most of this heat treatment is carried out by steel mills. Dehydrogenation treatment can not only eliminate excessive welding stress but also allow the diffused hydrogen in the welded joint to escape. Is the above content comprehensive? If not, please add to it; there are prizes for those who contribute.
Since you can find online information stating that it helps to remove hydrogen, eliminate welding stresses, improve the microstructure of welds, and enhance their overall properties, you can further investigate: What is hydrogen removal? How is welding stress formed? Methods for improving the microstructure and overall properties of welds might yield better results, hehe. I remember that the section on welding in the book \"Chemical Engineering Equipment Manufacturing Technology\" that I read during my studies likely contains the information you need. The book \"Engineering Materials\" discusses metal microstructures and heat treatment; unfortunately, I don’t have an electronic version of it, so you might want to look there. 1. Hydrogen removal treatment is aimed at eliminating hydrogen present in the welds during the welding process. This is usually done at around 350 degrees Celsius for 30 minutes, in order to reduce the damage caused by hydrogen to the welds. 2. Eliminating welding stress involves reducing the stress that results from the contraction of the weld during the welding process. This is achieved by heating, which lowers the stress generated during welding. The temperature required for stress elimination is relatively high, usually exceeding 600 degrees; this value can be calculated using tables, depending on the type of material and its thickness. The ultimate goal of welding heat treatment is to eliminate the residual stresses present in the welded structure, as many stresses are generated during welding and the rolling process of cylinders. Just as when bending a steel plate into various shapes, there is a limit to its plasticity; if these stresses are not removed, serious problems can arise during use, such as cracks and bulges. Therefore, heat treatment is an effective method for eliminating such stresses. Hydrogen removal – eliminates hydrogen molecules from the weld, to be carried out immediately after welding. Eliminate welding stresses, and perform fine machining after heat treatment, such as for tube boxes. Improving the weld structure and overall properties, such as the heat treatment of chlorine tanks and caustic soda storage tanks, is simply aimed at eliminating residual stresses after welding and enhancing the structural properties resulting from welding. If stress relief is not performed, cracks are likely to occur over time, along with a range of problems related to insufficient strength!
Heat treatment includes stress-relief heat treatment, as well as heat treatment aimed at restoring or improving mechanical properties. I’ve heard about these types of heat treatment before and am somewhat familiar with them; however, this hydrogen removal treatment is something I’ve seen for the first time – it was really informative. The detailed summary of information posted on the second floor was particularly helpful
This post was last edited by yujwlhh on 2020-6-1 08:50. Hydrogen removal treatment is carried out in advance by our unit during the actual pipeline construction process. When welding new and old pipelines together, hydrogen removal is performed first; then the old end is cut off, and no further hydrogen removal is carried out after welding the new end. Is there a difference between equipment manufacturing and pipeline construction, as mentioned by the original poster?
Dehydrogenation treatment doesn’t seem to fall under heat treatment, right? ? ?
What are the different types of heat treatment? What I’ve always remembered are post-welding heat treatment, heat treatment to restore mechanical properties, heat treatment to improve mechanical properties, and degassing heat treatment. However, the new 150 model (which isn’t really new either; it was released in 2011) does not involve any hydrogen elimination heat treatment. On the other hand, the 150 model from 1998 mentions something regarding hydrogen elimination heat treatment – specifically that heat treatment can be carried out immediately after welding, thereby eliminating the need for such treatment. So regarding this post, the answer is good, but there are still differences from the standard. If my answers are incorrect due to careless reading, please point it out. Thank you
It belongs to, and is also included in other heat treatments.
There is a section on heat treatment in the training manual for pressure vessel design engineers that covers this topic; after reading this post, I went and checked it out specifically. Thank you to the moderator for sharing.