Thousands of billets pass through an Aluminum extrusion press sleeve liner and core throughout its life cycle. Depending on the temperature and usage conditions, wear and tear occurs on these parts in the course of time. Below are the procedures to follow so that the sleeve liner and core have a long life cycle and protect their rigid structures:
Selection of high-quality steel,
Usage of modern heating systems,
Material processing with high-technique.
The sleeve is the component which acts as a bearing for the billet when the aluminum goes under pressure in the Extrusion press. The sleeve must conserve the heat of the billet, as well as its own heat, throughout the pressure period. Hot work tool steels which are resistant to the heat exchange occurring during the process must be preferred. The material of the sleeve must be of high-toughness and resistant to thermal shocks. Feeding this characteristic feature of the material with the appropriate heat treatment method has a positive impact on the lifetime of the sleeve and of the core as well. The toughness of the steel used increases the ability of the bearing action, thus the swellings that might occur in the core are retarded. The sleeve material retards the factors (swelling-generating belly) affecting the life of the core to the extent that it fulfills its duty as a bearing. The heating technique and the temperature control are as important factors as the selection of the sleeve steel. When the details are examined and the optimum methods are applied, extension of the lifetime of the sleeve and core is not a coincidence.
When heating the sleeve, it should not be exposed to thermal shocks. Heating up with the PLC control system should be preferred primarily. Sudden rises in temperature and cooling down might cause starting of micro crack formations. This could be observed particularly in the critical mechanical sections and the diameter transition areas of the sleeve. Therefore, it is indispensable to heat up and cool down the sleeve in a controlled manner.