Structural Integrity of Pressure Vessel Heads Made by Incremental Sheet Forming from High-Quality Steel P460 NL1

The fabrication of pressure vessel heads with large diameters necessitates the production from a starting sheet composed of two sections with weld joint.Subsequent plastic deformation may influence changes in the mechanical properties of the sheet, particularly the welded joint.The subject of this research is the effect of incremental plastic deformation (known as Incremental sheet forming) and post weld heat treatment on the mechanical properties of the heat-affected zone in the welded joint, as well as an assessment of the structural integrity.One of the goals of the work is to show that in certain circumstances heat treatment is not necessary.The researches focus on destructive and semi destructive testing of samples extracted from an actual pressure vessel head structure.The material of the vessel head is steel grade P460 NL1, and the heads are manufactured in two thicknesses: 6 mm and 14 mm.The results of the structural integrity assessment are presented in the form of a FAD diagram.