On the heat treatment of heat exchanger tube boxes
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Hello, fellow sailors! I have a question for you. For the tube box of a heat exchanger unit, the end caps on this tube box are made from materials supplied by our own factory; after the seams are welded, these end caps are spun into shape by an external contractor. These end caps come with test plates, and together with those test plates, they are heat-treated in the same furnace as the end caps themselves. Now that they have been returned to our factory, the tube box sections also come with test plates. All of the longitudinal and circumferential welds on the tube box have been completed, and it is now waiting for heat treatment. The heat treatment process is the same as that used for the end caps. I would like to ask whether these end cap test plates also need to be put into the furnace along with the tube box Is it really necessary? Will further heat treatment have any impact on the material properties of the head?
What is the reason for heat treatment of this tube box? Is it stress-relief heat treatment using partitions (or large lateral openings), or normalizing heat treatment to restore properties?
Hehe, I really don’t know. However, this official box has partitions, and the materials used at the bottom are all normalized plates. The process involves overall heat treatment of the official box. The official tank has dimensions of Φ2700×24, with the pipe connection opening being Φ819mm.
In my opinion, there are some issues with the manufacturing process; it should be done by first aligning the formed component with the cylinder, partitions, and flanges, and then subjecting the head material specimen to overall normalizing heat treatment along with the rest of the component
Well, you’re right; that’s what the standards state – heat treatment should be carried out together after shaping. But this is how things are done in our factory. So do you think it’s still necessary to subject the end cap test plates to heat treatment along with the rest in the furnace?
Hehe, I’m all learning from fellow sea lovers*.
It is necessary, otherwise who knows the condition of the material after it comes out of the furnace. What material? Ordinary low-alloy steel is manageable, but it becomes more problematic if there is a tendency to reheat cracking. I’ll say it gently: your factory is great, no, no, it’s your factory’s technical staff who are amazing