What causes such corrosion?
Thread Content
Dear Haiyou and all experts, please help analyze the reasons
The composite plate was welded without following the procedures, which probably caused problems in the weld or the adjacent composite layers
First, the welding defects are obvious; check the handover or maintenance documents. Secondly, it depends on the medium being stored or transported, and whether the selection of equipment material is appropriate. Third, based on the traces, it appears that the metal body in that area has been rewelded; it is necessary to investigate why rewelding was carried out, whether there are any defects in the material, or other reasons.
It turned out that it had been repaired by welding, using A102 welding rod; it was in operation for about two months, with boric acid, alkanes, and metaboric acid as the media
All product-related materials are qualified
Trust your own eyes; checking the item in person right away is far more accurate and effective than relying on the information you see.
I suspect there may be damage or quality issues with the internal composite layer.
There are issues with the repair welding process, and the welding rod chosen is not appropriate.
There was no welding procedure specification for the patch welding
What is the reason for the patch welding? Is it for new equipment or to fix defects that have arisen during operation? This kind of repair welding still needs to be carried out in accordance with the welding procedure specification determined after evaluation. Also, isn’t it a bit inappropriate to choose 102? What about the number of layers applied – could the molten pool end up melting the base layer as well? Personally, I think using a weld material with a high chromium and nickel content would be better