Understanding the Effects of Mechanical and Laser Cut-Edges to Prevent Formability Ruptures During Automotive Manufactur
- PDF / 1,896,790 Bytes
- 12 Pages / 595.276 x 790.866 pts Page_size
- 21 Downloads / 195 Views
TECHNICAL ARTICLE—PEER-REVIEWED
Understanding the Effects of Mechanical and Laser Cut-Edges to Prevent Formability Ruptures During Automotive Manufacturing Daniel J. Thomas
Submitted: 21 April 2013 / Published online: 15 May 2013 Ó ASM International 2013
Abstract The cut-edge condition has an important influence on the formability capacity of high-strength steel (HSS) automotive structures. XF350 and DP600 under examination were observed to display a decreased level of formability in the surface regions because mechanical punched edge hole-flanging capacity is dependent on ductility and the surface quality of the cut-edge produced. Formability was observed to be highly dependent not purely based on the properties of the steel but also the cut-edge properties. Hole expansion capacity (HEC)-forming experiments were performed on flat circular plates with mechanical and laser-cut holes to investigate the fracture and forming limits of HSS. The HEC properties of the cutedges were determined using mechanical and laser-cutting processes using various cutting process parameters in which certain edge types displayed decreases in edge ductility. It was found that, by altering the processing parameters during the cutting process, the edge quality can be improved, and this has a positive effect on the formability capacity of steel components. Keywords Forming HEC Hole expansion capacity Cut-edge forming Nomenclature A Elongation to failure AHSS Advanced high-strength steel HEC Hole expansion capacity HSLA High-strength low alloy HSS High-strength steel D. J. Thomas (&) Creation Engineering, Llynfi Enterprise Centre, Heol-Ty-Gwyn Industrial Estate, Maesteg, Bridgend CF34 9HA, UK e-mail: [email protected]
Ra Rp Rv wt
Arithmetic mean of departures from the mean line Maximum height of profile above the mean line Maximum depth of profile below the mean line Weight
Introduction During vehicle manufacturing, hole forming processes are used to form steels into in the required component shape [1–8]. HSS grades have lower ductility and cut-edge properties are increasing significant toward influencing level of formability [5, 6]. It is the cut-edge condition, tensile properties and microstructure of the steel that have a critical role in defining whether a component will split during the hole forming process. Further to this there is also a substantial level of variability in formability data, which may make it difficult to predict whether a component will split during fabrication as shown in Fig. 1. It is generally established that there is a trend that if the tensile strength of high-strength steels (HSS) increases, then the level of formability reduces. The level of formability decreases as the steel gauge thickness decreases, decreases as workpiece strength increases, and decreases as edge condition deteriorates [9]. As a result of these factors, the introduction of newer high-strength lighter gauge steel grades can result in a higher probability of edge splitting during manufacture. Mechanical cut-edg
Data Loading...
