3 Fundamentals of press design

6 Solid forming (Forging)
6.4 Formed part and process plan
Before producing a part by forming, processes (cold, warm, hot), process
combinations, processing steps, preliminary treatment, process plan
and intermediate treatment stages must all be defined. In addition, the
force and energy requirements, as well as relevant die stress levels have
to be computed. Only on the basis of these calculations it is possible to
define the press configuration concerning functional characteristics
such as press force, number of stations, distance between stations,
stroking rate, length of slide stroke and automation related questions.
In solid forming applications, processing frequently takes place at
the limits of physical feasibility for economical reasons. This applies for
example regarding the limits of material formability (crack formation,
strain hardening), the load capability of dies (internal pressures of up to
3,000 N/mm 2 ) and lubrication/cooling (cold welding). For this reason,
the economical application of solid forming depends to a large degree
on the experience of the designer and the die maker. With an efficient
combination of suitable finite element programs for process simulation
and existing factory floor experience, in metal forming plants a balanced
relationship can be said to exist between theory and practice.
6.4.1 The formed part
Lot size and materials
Solid forming represents a competitive substitute for machining
processes and in some cases also for casting processes (cf. Sects. 2.1.1
and 6.2.1). The high development costs and the degree of investment
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998