Deep Drawability and Bendability in Hot Stamping of Ultra-High Strength Steel Parts
The deep drawability and bendability in hot stamping of ultra-high strength steel parts were examined. Although the cold drawability is greatly influenced by the blank shape, the limiting drawing depths for the square and circular blanks were equal for hot stamping because of small flow stress. In hot hat-shaped bending using draw-and form-type tools, the effect of the blankholder force generated with the draw-type tools on the springback was small, and the seizure for the form-type tools was smaller than that of the draw-type tools. Since both edges in contact with the electrodes are not heated for resistance heating, cracks were caused at the edges for resistance heating in the transversal directions in hot stamping of an S-rail with form-type tools, and thus it is required to control deformation of the non-heating zones.
Danuta Szeliga and Krzysztof Muszka
K.-I. Mori et al., "Deep Drawability and Bendability in Hot Stamping of Ultra-High Strength Steel Parts", Key Engineering Materials, Vol. 716, pp. 262-269, 2016