Page 20 - MetalForming August 2012

Die Engineering
AT
...evolves to meet the challenges, and opportunities,
afforded by the growing use of advanced high-strength steels in automotive body-in-white structures.
BY J.P. MCGUIRE
With the new and ever-chang- ing international auto-safety standards, in addition to the need to keep vehicle weight low, mate- rial selection in body in white has rap- idly evolved at Chrysler. Responding to these new requirements, we have experienced the introduction of new advanced high-strength steels (AHSS) coupled with new manufacturing tech- nologies. Accommodating these changes to meet high-volume produc- tion and quality requirements has required development of new meth- ods of sheetmetal die engineering and stamping.
The Fiat Group/Chrysler alliance has been a key enabler for this rapid progress, as the sharing of a common vehicle platform has created synergies in the application of AHSS—grades possessing yield strength greater than 200 MPa. Recent global Fiat/Chrysler platforms use nearly 70 percent high-
J.P. McGuire, group manager, die design, automation and COC global standards, Chrysler LLC, presented at the recent Great Designs in Steel seminar, held May 16, 2012, in Livonia, MI. View his PowerPoint presentation, and those of all of the seminar’s speakers, at www.autosteel.org.
strength and advanced high-strength steels for their body structures (Fig. 1). New die-engineering standards were required to support this new product- engineering direction. These standards
focus on:
• Enhanced die structures to pre-
vent die failure/excessive deflection during operation;
• New advanced heattreatment, coating and die-material standards to prevent galling; and
• New standards for die manufac- turing, to accommodate new die-mate- rial practice, and updates to die-com- ponent usage calculations—for cams, stripping and pad pressure, binder ton- nage, flanging and piercing.
2012 PF C-Sedan BIW Material Usage
8%
4% 2%
Mild Steel HS Steel AHS Steel Hot Stamp Aluminum Other
Fig. 1—Recent global Fiat/Chrysler platforms use nearly 70 percent high- strength and advanced high-strength steels for their body structures.
30%
25%
30%
18 MetalForming/August 2012
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