Stress-relief heat treatment after welding for the 36mm-thick head (upper head); is heat treatment required for B1, which is connected to the upper head?
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As stated in the title: The upper head is 36 mm thick, while the cylinder wall is 30 mm thick. Is weld B1, which connects the upper head to the cylinder wall, subject to post-weld heat treatment? The head is to be trimmed, with a trimming ratio of 1:4 (5). I think it’s heat treatment. Reason: The welded components on heat treatment equipment are all heat-treated together with the equipment itself; for example, insulation pins, insulation rings, and reinforcement rings are all heat-treated after being welded. B1 has a thickness of only 30 mm and is also welded to the head; it can be considered similar to a thermal insulation nail, except that it features circumferential welds. My understanding is: all welds welded to the heat-treated head must undergo post-weld heat treatment! Seniors, is my understanding correct?
The thickness of the deposited metal is only 30 mm, so no heat treatment is required – do you understand?
Are the gusset plate weldments on the head heat-treated together with the head? Isn’t B1 welded to the head? It’s just that this weld is special – it’s a circumferential weld
“The welded components on heat treatment equipment are all heat-treated together with the equipment itself; for example, insulation pins, insulation rings, and reinforcement rings are all heat-treated after being welded. This understanding is also incorrect. For products that require overall heat treatment, the welded parts of the heat treatment equipment must be welded together with the main body before undergoing heat treatment. If the product itself has no overall heat treatment requirements, it is necessary to check each item according to the standards. Those that meet the requirements undergo heat treatment, while those that do not meet the requirements are not subjected to heat treatment.
I’m the one who made a simple problem complicated: dizzy:
On the contrary, you have raised a question that needs clarification, which makes things clearer. This is worth encouraging. ------------------------------------------------ The insulation nails welded to the head are required to be welded and heat-treated before heat treatment is carried out, as the wall thickness of the head exceeds the thickness required for heat treatment. The calculated wall thickness of the circumferential welds in that area has been adjusted to match the wall thickness of the cylinder section; in principle, no heat treatment is needed there. However, if the entire equipment is subjected to heat treatment, the overall performance of the welds will be better
Thank you, President Yu! :handshake
I somewhat understand what you mean regarding the concern about performing heat treatment before welding. Here’s the issue: according to your view, if the head needs heat treatment, then the insulation studs, insulation rings, reinforcement rings, and similar components that are welded onto it later also need to be heat-treated. But small manufacturing plants usually purchase the heads already heat-treated. What do you expect them to do? They would have to take those insulation studs, insulation rings, and reinforcement rings outside for heat treatment after welding them – which is hardly feasible. Additionally, it’s necessary to rule out other influencing factors first. You decided to carry out stress-relief heat treatment because the thickness of the weld metal at the head’s seams is 36 mm (assuming preheating is done, then there shouldn’t be any problems). The purpose of this heat treatment is to relieve stress in those seam areas; it actually has little to do with the insulation studs, insulation rings, reinforcement rings, etc., that are welded later. I’d appreciate some advice from @niat8888
There are two problems. If the head has no lap welds and is 36 mm thick, does the nozzle on the head also need to be heat-treated? If there is no takeover, is heat treatment then not necessary?