Keep warm

Holding is a term from the foundry branch of metallurgy .

Definition of terms

It is understood to mean that a melt is always kept at the required casting temperature in a special furnace, the holding furnace, from the moment it is made available for casting purposes and regardless of whether it is then used in smaller or larger time intervals to fill casting molds . This also applies during longer breaks in pouring or empty shifts.

Working method

Depending on the operational conditions, either several crucible furnaces are used as holding furnaces , which is common in chill and die casting foundries, or a large-volume furnace from which the casting metal is used, taking into account a temperature loss during decanting and filling the transport to the pouring point, if necessary, is filled into a pouring ladle with a capacity of 1000 or more kilograms. In practice, this occurs when the metal requirement is based on the piece weight of the cast parts (e.g. production of automobile wheels using the low-pressure casting process ).

Large-volume holding furnaces, which have a capacity of 30 tonnes or more in semi- finished products , often serve as a mixer at the same time when they take in several freshly melted batches and compensate for batch-related differences.

literature

• Ernst Brunhuber: Foundry glossary , Schiele and Schön GmbH, 17th edition, Berlin 1997, ISBN 3-7949-0606-3