On welding of dissimilar steels
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During the design of composite plate pressure vessels, the issue of welding different types of steel often arises; to avoid such welding, methods such as modifying the structure are employed. Has any expert summarized and studied what the hazards associated with welding dissimilar steels are? Under what circumstances is welding with dissimilar steels absolutely prohibited, and when is it permissible? Thank you!
This isn’t something that can be explained in just a few words. It is recommended that you enroll in a training course to learn systematically.
The problem with composite plates does not lie in welding different types of steel, but rather in the fact that the cladding of conventional composite plates cannot be heat-treated. Taking austenitic stainless steel composite sheets as an example, both cold forming and hot forming inevitably lead to a weakening of the heat treatment condition on the austenitic stainless steel side; cold forming causes deformation martensite to appear in the composite layer, while hot forming makes it difficult to avoid the sensitization range. As a result, the overall corrosion resistance of the composite sheet is bound to decrease to some extent. Therefore, austenitic stainless steel composite plates are suitable for applications where high strength is required, but corrosion resistance is not an extremely strict requirement.
The main issue with composite plate containers is the material selection for small-diameter fittings, as welding of different steel types can pose problems
I haven’t been able to figure it out, but it seems what you say makes sense
This post was last edited by wanlirn on 2020-7-7 at 13:50. Welding in composite plate pressure vessels is different from welding of dissimilar steels as generally understood; there are established welding structures and methods for the butt welding of the vessel cylinder and for opening holes in nozzles. In 47015, stainless steel and titanium are involved； Nickel-zirconium composite plates are also specified in the relevant standards for containers