Sheet Metal Forming

part edge quality, 4–5(F), 6(F)
scratching tests, 330
tool materials, 120(F)
tooling construction, 122(F), 125–126(F,T)
total elongation (EL), 108(F), 109, 112–113
TOX Pressotechnik GmbH, 294(F)
tractrix die bending, 31(F)
transfer die forming
overview, 73
transfer die set, 74(F)
transfer dies, 13, 73, 74(T), 79–81(F), 82, 83
transfer presses, 124(F)
transformation-induced plasticity, 142
transformation-induced plasticity (TRIP) steels, 107
at elevated temperature, 113
flow stress, 109
K-B equation, 119
strain rate, 112
TRIP 780, 109
TRIP 800, 113, 115
Tribology in forming AHSS
lubrication
dry film lubricants, 120

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Index / 363
overview, 119–120
wet lubricants, 120
overview, 119
tooling
surface treatment effects on tool wear, 120(F)
tool coatings, 121–122
tool coatings for stamping, 123(T)
tool material for forming DP 600, 121(T)
tool material for forming DP 800, 121(T)
tool material for forming DP 1000, 121(T)
tool materials, 120–121
tool steel materials selection, 121(T)
tool steels as inserts in cast iron die, 122(F)
U-channel drawing of dual-phase steels, 120(F)
workpiece—sheet metal, 119
failures in forming AHSS/ultrahigh-strength steel, (F)
tube bending
bending methods, 187, 188(F)
defects, 187
overview, 185
parts that require preforming, 186(F)
process characteristics, 185–186
rotary draw bending, 187–189(F), 190(F,T)
springback, 186
thickness distribution, 186(F)
tube hydroforming presses
optimization of the integrated forming process, 197(F)
overview, 193
press frame designs, 194–197
production line, 194, 195(F)
productivity enhancement, 197(F)
tandem press, 198(F)
tube hydroforming press concepts, 196(F)
tube hydroforming (THF). 
See also
tube bending
advantages, 179–180
applications, 179
automotive industry, 179, 180(F)
characteristics, 193
classification of, 180–181(F)
design guidelines, 202, 205–206
classification of formability of tubes, 207(T)
expansion percentage limits, 206(T)
formulae for tube hydroforming, 206(T)
general guidelines, 206(T)
drawbacks, 180
examples, 180(F)
failures, 202, 203(F)
flow stress, 183–185
formability, 182–183
formability tests
biaxial tube bulge test, 183–184(F), 185(F)
cone expansion test, 183(F)
hoop test, 182, 183(F)
hydraulic bulge test, 182–183(F)
tensile test, 182, 183(F)
friction and lubrication
die-workpiece interface variables, 192(F)
overview, 192
friction and lubrication, parameters
increased interface pressure, 193(F)
increased sliding velocity, 194(F)
interface pressure, 192
parameters that influence, 193(F)
sliding velocity, 193
surface expansion/contraction, 192
friction zones, 193, 194(F)
materials for
aluminum alloys, 182(T)
overview, 181–182
steel alloys, 182(T)
mechanics, 189–192
process control limits, 190(F)
punch force components, 191(F)
simple part, 190(F)
state of strain on the bulge shape, 191(F)
overview, 179
presses (
see
tube hydroforming presses)
process sequence, 179(F)
seamless tubes, 181
as a system, 181
system components, 182(F)
tube bending (
see
tube bending)
welded tubing, 181–182
tube hydroforming (THF) process design
AS approach, 204–205
adaptive simulation procedure, 205(F)
flow chart, 205(F)
failures, 203(T)
loading paths, 202
overview, 202
SF approach, 202–204(F)
pressure curve and axial feed curves, 204(F)
simulations, 204(T)
tube hydroforming tooling
classification of
closed die, 197, 199(F)
crosswise split dies, 197, 199(F)d
lengthwise split dies, 197–198, 199(F)d
open die, 197, 199(F)
production dies, 198–199, 200(F)
prototyping dies, 198, 200(F)
optimization of the integrated forming process,
197(F)
overview, 193
production line, 194, 195(F)
productivity enhancement, 197(F)
tool design consideration, 199
factors to be considered, 201(T)
pressures generated in the guiding zone, 200(F)
T-shape tube hydroforming die, 200(F)
tooling composition, 198(F)
tooling parts, 199(T)
tube hydropiercing, 199, 201–202
design considerations, 202(T)
engine cradle ready for installation, 201(F)
engine cradle with multiple holes, 201(F)
inward hydropierced holes, 201(F)
outward hydropiercing, 202(F)
tungsten inert gas wire (HTCS-Rod), 152
twelve-node shell element, 144

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