Grooving issues for welding grooves in CS and SS composite plates
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Dear experts, regarding the grooving of welding grooves for CS and SS composite plates, I have the following questions: 1. Is it necessary to groove the welding grooves of composite plate materials? As shown in the figure below. 2. Regarding the portion of the groove that has been removed, a transition layer is welded in place. Can this area be taken into account in the strength calculations? That is, when calculating the strength of the shell, should the minimum thickness of the base material after the removal be considered? Should the transition layer and the welded portion also be included in the strength calculation? How should the allowable stress be determined?
Regarding this issue of opening grooves, I have also encountered the same problem as the original poster. It is understood that different manufacturers use different methods. Some directly make grooves without cutting grooves in the transition area, while others still perform grooved welding to ensure welding quality. It seems that all the drawings for the compound show grooves. Regarding the second question from the original poster, it is about calculation. You’re overthinking this. Not to mention factors such as the small size of the grooves or the fact that the welding rods used for the transition layers are of SS grade, why do GB150 and related standards specify minimum requirements regarding the impact energy of the materials? It is to improve the properties of materials (steel plates, forgings); the aim of enhancing these material properties is to provide a margin for welding joints in order to ensure product quality. Therefore, the question raised by the original poster regarding the calculation of strength takes into account safety factors, the mechanical properties of the materials, and the requirements regarding impact energy. For calculations, it is sufficient to use the thickness of the base layer; there is no need to consider the impact of the groove dimensions.
However, for grooving in longitudinal and circumferential weld seams, the base material does thin by 1–2 mm. When filling the weld seam, a transition layer such as E309 is generally used, and its properties differ from those of the base material. Is the strength of this area not taken into account due to the grooving?