3 Fundamentals of press design

378 Sheet metal forming and blanking
Example:
When roll forming with 2 mm thick strain hardened sheet steel in St 37-2
(material number 1.0037) with the modulus of elasticity E = 2.1 · 10 5 N/mm 2 for
steel and yield strength R eL = 220…240 N/mm 2 the useful radius range is calculated
as follows:
2mm ⋅2. 1⋅10 N/ mm
ri
max =
2
2 ⋅240
Nmm /
r = 2mm⋅ 05 . = 1mm
i min
5 2
210, 000
= mm = 875 mm
240
The actual radius when bending at right angles to the rolling direction should
thus be at least 1 mm in size.
Fig. 4.8.18
Step-by-step manufacture of
a section using 20 rolls
(flower diagram)
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998
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