After the installation of the heat-treated composite panel equipment, minor welding repairs are required in some areas inside; is local heat treatment necessary after these repairs?
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At present, all the equipment in the unit has been installed. In some of the composite plate equipment, there is a small amount of base material and weld seams that require re-welding. Are there any new standards or regulations regarding the locations where re-welding is to be carried out, or regarding whether local heat treatment is necessary after such repairs? If not needed, could you please let me know the standards and regulations? Thank you all!
I did not see any standards specifying the location for repair; after repair, heat treatment can be carried out in accordance with Clause 4.7 (P109) of NB/T47015-2011. It is recommended to use nickel-based welding electrodes for repair, without performing local heat treatment.
Could you explain in detail why it is possible to repair or weld using nickel-based alloy electrodes without the need for further local heat treatment? I once read a paper on a welding method that involves tempering of the weld seam, which eliminates the need for heat treatment; however, this method leads to excessively high hardness in certain areas of the weld seam as well as increased local stress!
Could you explain in detail why it is possible to repair or weld using nickel-based alloy electrodes without the need for further local heat treatment? I once read a paper on a welding method that involves tempering of the weld seam, which eliminates the need for heat treatment; however, this method leads to excessively high hardness in certain areas of the weld seam as well as increased local stress!
It depends on the specific situation. Generally speaking, for the surface of composite panel claddings and the welds on those claddings, repair and grinding are sufficient; local surfacing can be carried out, and no post-weld heat treatment is required, unless there are special requirements for the base material. The post-weld heat treatment of composite plate containers does not benefit the corrosion resistance of the coating.
Generally speaking, this term doesn’t seem very convincing! Are there any document standards or specifications to support this? The issue of the decline in corrosion resistance due to post-weld heat treatment of composite panels is outside the scope of discussion here; moreover, this is determined by taking many factors into account!
So, it’s necessary to analyze each specific situation individually. The exact material grade of the composite panel, the specific design requirements for the container, the properties of the medium, operating conditions, and so on – detailed and specific information is required in order to come up with a tailored solution. A brief explanation will only allow for general statements
Indeed, as mentioned above, it is necessary to clearly explain the status of the equipment; this will facilitate everyone in conducting specific discussions and analyses based on the actual circumstances, and in providing suggestions. Furthermore, such equipment design documents generally should include manufacturing technical documents, which should specify whether post-weld heat treatment is required for repairs.