3 Fundamentals of press design

Casting components for presses
Fig. 3.7.1 Eccentric wheel of a large-panel transfer press
both of metallurgical and casting technology. Maximum care in the
production process is an underlying requirement. According to the current
state of the art in the field of foundry practice, the following stringent
requirement criteria can be covered with GGG-70:
– high resistance to wear, i. e. the microstructure must be purely perlitic
even with wall thicknesses of up to 200 mm,
– guaranteed hardness of 240 to 300 HB in all wall thicknesses – also at
the tooth root,
– elongation over 2 % in order to avert fractures and to increase resistance
to overloading.
In its raw cast state, i.e. without transformation annealing, these
mechanical requirements are achieved using a selective alloying technique.
The application of cooling elements made of iron, steel and silicon
carbide, either cooled or uncooled, also serves to enhance hardness.
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