Journal Article
Forming Limit Diagrams of Ground St14 Steel Sheets with Different Thicknesses
2012-04-16
2012-01-0018
The influence of sheet thickness on sheet metal forming limits is a controversial issue; while some investigations indicate the considerable influence of thickness on forming limit diagrams (FLDs), others suggest that it is of negligible importance. In the present work, it has been demonstrated that if the thickness-reduction process is chosen so as not to alter the micro structure of the material, the forming limits do not change with variations of thickness. A material which has extensive usage in sheet metal forming processes of automotive industry (St14) has been provided. The initial thickness of the sheet is 1.5mm and using grinding process (which does not alter the microstructure) the initial thickness is reduced to different thicknesses, namely 1 and 0.5mm. Afterwards, the FLDs for all three thicknesses were determined using standard test methods. The FLDs for specimens which were ground to various thicknesses differ slightly.
