0
Research Papers

An Innovative Shearing Process for AHSS Edge Stretchability Improvements

[+] Author and Article Information
Hua-Chu Shih

 Automotive Center, United States Steel Corporation, Troy, MI 48098-2692hshih@uss.com

Ming F. Shi

 Automotive Center, United States Steel Corporation, Troy, MI 48098-2692mfshi@uss.com

J. Manuf. Sci. Eng 133(6), 061018 (Dec 15, 2011) (8 pages) doi:10.1115/1.4005460 History: Received March 30, 2011; Revised November 17, 2011; Published December 15, 2011; Online December 15, 2011

A beveled shear hole piercing process has recently been developed for advanced high strength steel (AHSS). The preliminary results have shown the new process is able to improve the quality of the sheared edge and the edge stretchability of AHSS. The goal of the current study is to optimize the beveled shearing process and identify the optimal shearing conditions for AHSS. Four different advanced high strength steels, including DP600, DP780, TRIP780, and DP980 with various thicknesses together with a conventional high strength steel, HSLA50, are selected in this study. The hole expansion test is used to evaluate the effect of shear edge conditions on the edge stretchability. The results show that an optimal selection of the die clearance and the shearing angle results in a less damaged edge, which significantly delays edge fracture in the forming process and increases the edge stretchability for AHSS. To further validate the advantages of the beveled shearing process in improving the shear edge quality of AHSS, a straight edge shearing device with the capability of adjusting the shearing variables (rake angles and die clearance) with respect to different sheet thicknesses was also developed and built. The edge stretchability of the straight edge sheared specimen was then evaluated using the sheared edge tension test. A similar trend to the beveled shear hole piercing process of AHSS is observed, and a significant improvement in the edge stretchability is also obtained with optimal shearing conditions.

Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 10

Comparison of peak load between different punch configurations

Grahic Jump Location
Figure 11

Microhardness profile of the SAZ performed at the middle of the burnish zone for DP780 [13]

Grahic Jump Location
Figure 12

Schematic illustration of straight edge shearing device

Grahic Jump Location
Figure 13

(a) Photograph of the straight edge shearing device, (b) Diagram of the test specimen, and (c) Photograph of the sheared specimen

Grahic Jump Location
Figure 14

The sheared specimen of the straight edge shearing test

Grahic Jump Location
Figure 15

Comparison of the shear load between different shear rake angles

Grahic Jump Location
Figure 16

Comparison of the shear load between different upper and lower blade rake angles

Grahic Jump Location
Figure 17

Comparison of total elongation between different shearing conditions

Grahic Jump Location
Figure 18

Different failure modes in the SET test

Grahic Jump Location
Figure 8

Different configurations of the concept punch

Grahic Jump Location
Figure 7

Comparison of peak load between different shearing speeds

Grahic Jump Location
Figure 6

The HER at different shearing speeds for all tested materials and thicknesses

Grahic Jump Location
Figure 5

Variations of the HER with shearing conditions for different tested materials

Grahic Jump Location
Figure 4

Variations of HER with die clearance for different thickness (DP980)

Grahic Jump Location
Figure 3

Variations of HER with die clearance for different thickness (DP600)

Grahic Jump Location
Figure 2

Schematic diagram of the hole expansion test

Grahic Jump Location
Figure 1

Schematic illustration of hole piercing die set

Grahic Jump Location
Figure 9

Variation of HER with different punch configurations for different materials

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In