Manufacturing Process
Manufacturing Process
The production process starts from the Technology Office, where the construction and the casting technology is worked out.
The structural and technological study is supported by the computer system with modern programs.
The documentation is sent to the pattern-shop, where the casting models are made.
The models are made of wood, aluminium, plastic and recently of foamed polystyrene.
The machine park in the pattern-shop makes it possible to make big-dimension castings with the dimension up to 4000 x 4000 x 3000 mm or 4200 x 3000 mm.
The Foundry has two production workshops:
- 2 x 20 m wide, 220 m long, 12 m high, equipped with cranes with the capacity from 5 t to 75 t.
- 20 m wide, 40 m long, 6 m high, equipped with cranes with the capacity of 3 t.
The casting forms are hand-made in the technology of self-hardening loose masses prepared in a mixer-loader with the productivity of 15 t/h and 6 t/h. The forms for smaller cast-iron castings are made in the bentonite masses prepared in a blending engine for masses. This technology is used only in the Small Inductive Foundry. For the forms made of self-hardening masses, chromite masses prepared in a separate blender are used locally. The moulding shop has a series of box mouldings, which enables to make forms with the maximum dimensions of 4000 x 4000 x 3000 mm and exceptionally with a strickle board to O 5000 x 1000 mm.
In the Big Foundry the metal is smelted in the arch furnace with the capacity of 20 t and is cast into a bottom stoppered ladle 20 t and 30 t and a tilting ladle 15 t /for spheroid and grey cast-iron/.
In the Small Foundry metal is smelted in the inductive furnaces with the capacities: 200 kg and 500 kg and it is cast to tilting ladles 0,5 t and 1,0 t.
In the process of smelting the cast steel in the arch furnace, oxygen-gas burner with 1,0 MVA is used for heating the batch and helping the melting. And freshing the cast-iron is made with oxygen by means of a manipulator controlled from the furnace cabin. The manipulator is also used for carbonating the metal with the powder carbonator. Smelting the metal in the arch furnace is controlled by the processing computer, which takes into account the optimalisation of smelting parameters, the consumption of electricity, gas, oxygen, ferroalloys, examining the chemical composition etc. The above information is kept in the archives.
The big container of liquid oxygen / capacity 30 t / enables its use not only in the metallurgical process but also in burning big riser heads and in preparing the batch from non-batch scrap metal. The metal cast into a bottom stoppered ladles is exposed to argonating through a gas-letting shaper installed at the bottom of a ladle.
Additionally in the ladle we apply disoxygenating, desulphating and the modification of cast-iron and steel-iron.
The forms are cast in an argon cover with the use of pouring cranes with the capacity of 75 t.
The casts are knocked out from the forms on a knock out grid and taken apart by means of a crane.
The heat treatment of the casts is made in a modern annealing furnace with the size 4200 x 4000 x 5000mm, and in a small annealing furnace with the size 1200 x 800 x 2000 mm. The heat treatment is controlled by a computer with the full visualization and archivization of the data. The suitable computer program enables the heating, warming and cooling the casts and the furnace according to the established process of the heat treatment. The modern annealing furnace was built in 2004 and co-financed by the European Union PHARE.
The casts are cleaned by hand and by sanding and shot blasting equipment /a shot blast unit/. The mechanical treatment of the casts is made on the basis of the Foundry's own machine park /lathes, milling machines, drilling machines/ and in the cooperation with the nearby mechanical plants /turning and boring lathes - max. O 6000 mm, boring lathes, planning machines, slotting machines/.
The castings are covered with paint according to a client's needs.
