How does a foundry work - Zanardi Fonderie - part 3

Se ti interessa guardare il nostro video in lingua italiana clicca questo link: • Find out more about our project: • Here are some products installed by our technicians: JAES is a company specialized in the maintenance of industrial plants with a customer support at 360 degrees, from the technical advice to maintenance, until final delivery of the industrial spare parts. Linkedin: ​ Facebook: This last episode of the series focuses on the operations carried out on freshly cast iron castings, such as deburring. Deburring is the mechanical operation, which can be carriedout both manually and mechanically, through which the “burrs” present on the workpiece are removed. Before carrying out the deburring operations, all the cast iron castings exiting the foundry line undergo an initial quality check which includes a visualinspection and a hardness check. Once checked, the workpieces are divided into lots, collected within specific bins for internal handling and suitably identified with a code useful to perform all the subsequent phases. Painting is another operation that is carried out at the Zanardi Fonderie production plant. The painting of a cast iron object may be required both for an aesthetic factor and to protect its surface from possible damage related to the external environment, such as rust. There are several ways to paint, Zanardi Fonderie use the immersion in water-based paint Fonderie is equipped with an automatic painting line. The operators place the individual objects to be painted on poles hooked to a mobile chain. These first go througha tunnel where they are washed to remove impurities. Then they go through the painting booth where, by means of 2 lowerators, the workpieces are completely immersed in the tank; they are then manually finished where necessary. Then they go through 2 ventilated furnaces for the reticulation of the paint and then be unloaded by the operators. Even after deburring and painting, the raw cast is not usually ready to be used by the customer. Workpiece mechanical and finishing processes are carried out with different machinery according to the type of operation required. Very often this phase is not carried out within a foundry but subcontracted to external mechanical workshops; instead, Zanardi Fonderie has developed its own mechanical workshop within the company, with 5-axes lathes for complex mechanical processing such as turning, toothing and drilling. Let us now continue our journey inside the Zanardi Fonderie production plant. A further and important process present within Zanardi Fonderie is the austempering heat treatment. The austempering heat treatment is usually carried out by companies specialised in heat treatments and not by foundries which subcontract this process. Instead, Zanardi Fonderie has been carrying out this process internally since the beginning of the new millennium, both for its own castings but also for the castings of other foundries. Being a foundry with in-house heat treatment makes it unique as a company in this treatment makes it possible to give the spheroidal graphite iron mechanical properties comparable or superior to those of quenched and tempered steel, maintaining the typical lightness of ductile iron and its natural capacity to adapt to the manufacture of complex moulds. The material obtained after the heat treatment is called Austempered Ductile Iron, also known as ADI. To obtain a casting in ADI, it is necessary to treat the spheroidal graphite iron casting suitably enriched by alloying elements such as copper, nickeland us now see how the Austempering cycle takes place:The operators load the treatment baskets with the cast iron castings which initially undergo a pre-heating in a specific furnace placed in front of the austempering furnace. The basket reaches the uniform temperature of about 600°C, it is then picked up by an automatic conveyor and transferred first into the vestibule and then into the intermediate washing chamber, where all the oxygen and salt vapours are eliminated; then the basket with the workpieces moves to the austenisation chamber, where the heating phase takes place, reaching an optimal temperature for thediffusion of carbon in the austenite, typically between 800°C and 900°C, everything takes place in a controlled ENDOGAS atmosphere, composed of hydrogen, nitrogen, carbon monoxide and a compound of carbon dioxide, methane and water. At the end of this phase, the material passes from a generally pearlitic matrix to a completely austenitic one rich in carbon. Once austenisation is complete, the basket moves back to the intermediate washing chamber, without coming into contact with the external environment, then returns...
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