The objective of this work has been to establish a profound knowledge about design rules for projection welding geometries dependent of the actual material combination.Design rules and recommendations for geometries and projections in projection welding given in literature is summarised and these are catalogued into geometry-classes. A simulation software, SORPAS, based on the finite element method (FEM) is chosen as tool to investigate projection weld quality. SORPAS needs input of the material flow stress as function of strain, strain rate and temperature. Flow stress experiments are performed using a thermo-mechanical simulation machine (Gleeble machine)for stainless steel (W. no. 1.4301) and mild steel (W. no. 1.0037) for temperatures between 20 °C and 1300 °C and for free cutting brass (W. no. 2.0401) for temperatures between 20 °C and 800 °C. Two different strain rates, 10 s-1 and 25 s-1, have been investigated.Two different welding geometries, disc with triangular ring projection welded to ring and hat welded to inside hole in ring, are both experimentally and numerically used to investigate the influence of different geometric parameters (thicknesses and angles) on weldability and weld strength when welding different material combinations (stainless steel to stainless steel, mild steel to stainless steel, brass to stainless steel and stainless steel to mild steel). The investigations show that geometric parameters and material combinations have great influence on the weldability and the weld strength. Based on the investigations some general design rules for the two geometries has been recommended.
Main Research Area:
Department of Manufacturing Engineering, Technical University of Denmark, 1999