Why are stainless steel composite panels not allowed to be joined? What is the impact of stitching?
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The cylinder body is made of stainless steel composite plates (created by explosive bonding; the width of the stainless steel coating layer does not exceed 1500 mm). To prevent the circumferential seams of the cylinder body from coming into contact with the nozzles, the width of each cylinder body section is set at 1800 mm, which results in joints in the stainless steel coating layer. However, the customer requires that the composite plates have no joints at all. Why is it not allowed for composite plates to have joints? What is the impact of stitching? What are the solutions?
Stainless steel composite panels can be joined together; who says they can’t?
If rolling compounding is used, the laminates generally are not allowed to be spliced. If explosive bonding is used, it can be joined. Requirements for splicing laminated materials: a) Welding shall employ a qualified process. b) The two steel plates joined together should be flat, with the misalignment of the welds being less than 0.5 mm. c) 100% radiographic testing shall be performed on the butt weld joints. d) The surface of the composite face welded joint shall be polished smoothly and subjected to 100% penetrant testing.
I’ve never used composite panels, but I have used composite pipes. It seems that at both ends of the composite tube, over a distance of about 100 mm, the welded stainless steel layer needs to be removed through machining, followed by re-welding and further machining; in other words, the composite plates at the ends of the tube are manufactured differently from those in the middle section.
Why are composite steel plates not allowed to be joined? After the cylinder is rolled, its longitudinal seams must be welded anyway – what’s the difference between that and splicing? The key is to control the amount of misalignment during splicing.
The cladding steel plates for composite panels are usually steel strip coils with a width of 1500 mm; if splicing is not allowed, the width of the composite panel after manufacturing will be around 1400 mm, which is not worth it. If the design imposes requirements on the lap welds of the cladding, inspection requirements for those lap welds can be specified; it is unreasonable to prohibit laps.
Unless required by the owner or the design team, splicing is permissible, but special consideration must be given to the splicing joints.
Composite panels can be joined together. The joint groove is required to undergo PT testing; the base material is required to have RT testing performed, and the cladding layer is also required to undergo PT testing
In fact, whether it is carbon steel or stainless steel, the properties of the welds and heat-affected zones are more or less affected, making it difficult for them to match the overall properties of the base material. In particular, the properties of stainless steel welds are greatly affected; it is beneficial to minimize welds in order to ensure corrosion resistance. However, the joining of the coatings on composite panels is also inevitable. As a designer, specific inspection requirements can be specified for the butt welds.
What the original poster is referring to is the joining of stainless steel plates before blasting, which is something different from what you mentioned
:)Communication is important; explain the actual situation to the users. To close a business deal, it doesn’t necessarily rely solely on technical skills; diplomatic and coordination abilities are also crucial