Page 30 - 3D Metal Printing Summer 2019

3D FEATURE
AM Tooling Key to
Hot Stamping
Success
3D printed tooling enables incorporation of complex cooling channels required to regulate material temperatures during the
hot stamping process. As the automotive industry increasingly adopts hot stamping,
opportunities grow for AM tooling.
BY LOUIS A. KREN, SENIOR EDITOR
Within the past decade, hot stamping has gained
a foothold in North America, as more and more automotive OEMs and their Tier suppliers adopt the technology. Efforts in automotive lightweighting and safety-cage improvement have coincided with intro- ductions of ever-stronger advanced and ultra high strength steel (AHSS, UHSS), and the combination has revealed hot stamping as the process that most efficiently produces— and many times the only process that produces—complex, safety-critical components. Common hot stamped compo- nents include A and B pillars, and roof reinforcements, and as the technology becomes more ubiquitous, more part appli- cations surface.
Describing the process in its most general terms, steel blanks feed into tunnel or stacked furnaces for heating to a temperature (above 1500 F or so) that makes the blanks malleable. Blanks move into a press capable of controlling stroke rate and dwell time for forming, followed immediately by in-die quenching for 3 to 10 sec.—in-die water channels often serve this purpose. The heating and quenching processes—the former shifting the steel to a full austenitic phase followed by the latter for trans- formation to a full martensitic phase—create the hardened mate- rial while not overly stressing the tooling, thus the material can
28 | 3D METAL PRINTING • SUMMER 2019
3DMPmag.com
A hot stamping die at Urgent Design & Manufacturing in Lapeer, MI, awaits a red-hot blank. Rest assured it’s coming, as hot stamping has taken off and continues to grow in North America.
be formed more easily prior to reaching its final hardened state. Increasingly used in hot stamping is tooling produced via 3D printing, the only viable process for producing complex cooling channels. The connection between additive manufacturing (AM) and tooling, and more, will be detailed at the Hot Stamping Experience and Tech Tour, September 17 in Lapeer, MI, sponsored