Can local heat treatment be used to eliminate welding stress?

It can be heat-treated in sections, but it is best to also perform local heat treatment on the joints.

For the equipment, it is called local processing, but for circumferential seams, they should be processed entirely at once.

However, the flange is a large-diameter forged part with a diameter of 4900; we do not have the capability to carry out heat treatment on it as a whole at once. Are there any other methods to eliminate welding stress? ? ? This post was last edited by fjfg on 2009-2-13 08:06.]

In my opinion, local heat treatment should be possible!

Can’t heat treatment be carried out using an electric heating strip?

Segmented heat treatment imposes requirements on the equipment; if the design drawings specify overall heat treatment, it cannot be segmented. However, the circumferential welds can be subject to localized heat treatment

Article 73 of the Code stipulates that the post-weld heat treatment of steel pressure vessels shall meet the following requirements: 1. High-pressure vessels, medium-pressure reaction vessels and storage vessels, horizontal storage tanks for storing mixed liquefied petroleum gas, and mobile pressure vessels shall undergo overall heat treatment in a furnace. Other pressure vessels shall undergo overall heat treatment. For large pressure vessels, segmented treatment can be employed; the length of the overlapping heat-treated sections should be no less than 1500 mm, and insulation measures should be applied to the parts outside the furnace. 2. Local heat treatment can be used for the circumferential weld joints that have been repaired, as well as for the weld joints connecting the nozzles to the vessel body or heads. For welds that have undergone local heat treatment, the entire weld must be included. The heating width on each side of the weld shall be not less than 2 times the thickness of the base material; when joining a pipe to the shell, the heating width shall be not less than 6 times the thickness of the thicker of the two components (the larger value being taken). The housing near the heating area should be insulated to prevent large temperature gradients from forming. For text that changes color, the device can process it in segments; however, this is not possible for circumferential seams, which must be processed as a whole. Last edited by gzk1986 on 2009-2-13 11:02.]

However, I have found that in the drawings of many pressure vessels, there is no requirement for heat treatment to relieve welding stress in this ring weld

Agree with the opinion on floor 9. The entire circumferential seam can be heat-treated at once.

So how does this work? There’s no need to put the entire container into the annealing furnace, right? It seems that electric heating can be used; just heating it around the edges should suffice

Local heat treatment can be carried out, but the heating width must comply with the relevant provisions of JB/T4709.

It depends on what type of container it is. If it’s a tower-type vessel, heat treatment can be carried out in stages; however, this is absolutely not possible for spherical tanks. For ordinary tank-type containers, it depends on the nature of the medium contained within them. If the medium is extremely or highly hazardous, heat treatment must be performed as a whole, with no segmentation allowed.

Ring welds can be heat-treated in segments – which standard specifies that? Come on.

The tolerance standards require that electric heating strips shall not be used for heat treatment of weld changes.

According to clause 10.4.5.3 of GB150, since the aforementioned welds belong to Class B, local heat treatment is permitted

Local heat treatment can be employed, with the repeated heating length being no less than 1500 MM. Insulation measures should be applied to the parts of the container outside the furnace in order to avoid excessive temperature gradients.

Clause 10.4.5.3 of GB150-98 \"Steel Pressure Vessels\" stipulates that local heat treatment is permitted for welding joints of categories B, C, and D, welding joints of category A where a spherical head is connected to the shell, as well as areas that have been repaired due to defects. So I think local heat treatment can be carried out.

In my personal opinion, if the cylinder is not under pressure, local heat treatment can be applied.