A prerequisite for exploiting the lightweight construction potential of cast iron and steel

components is the production of thin-walled, weight-optimized castings. Due to their high

component strength, ductility, and component integration through casting, cast steel

components can achieve weight savings of 30% compared to joined sheet metal constructions

used in the automotive sector, for example. Until now, thin-walled steel castings have been

produced using the investment casting process, although market penetration was limited due

to the high costs of producing large, moulded shells. The low-pressure casting process

considered in the joint project offers the advantage of casting more complex components from

iron and steel alloys with significantly lower wall thicknesses and technically interesting flow

lengths thanks to the reproducibly controllable casting process (compared to gravity casting).

A further advantage is the saving of up to 30% in circulation material, because complex sprue

systems and feeders are not required in the low-pressure casting process. A new concept of a

low-pressure casting system will be presented, which allows the use of thin, shell-like sand

cores using a moulding material carrier, thus significantly reducing the amount of moulding

material required. New inorganic binder systems were developed that withstand the

conditions in iron and steel casting and meet the requirements to produce sand cores in 3D

printing and core shooting processes, thus creating the prerequisite for industrial

implementation in the series process. These inorganic systems offer the advantage of being

able to work with preheated mould materials. This makes it possible to further reduce wall

thicknesses for both conventional gravity casting and low-pressure casting, thereby increasing

the lightweight construction potential for applications in iron and steel casting. Filling

simulations for a demonstrator component show the influence of preheated mould shells and

serve as a basis for the design of the thermal control of the mould material carrier. The

development of the new low-pressure casting process with the use of inorganically bound

moulding material shells is accompanied by a profitability analysis and a comprehensive

consideration of the processes to assess the ecological effects and economic aspects

associated with the introduction of the technology.