Fondinox > Centrifugal Castings

Centrifugal Castings

Centrifugal casting is a process that delivers shaped castings very near to the final dimension and of high material soundness. It is the best choice for the production of critical components where a high grade of reliability is required.

In the centrifugal casting process, liquid steel is poured into a spinning metallic shaped mould. Centrifugation leads to:

  • Mechanical separation of inclusions and impurities towards the internal surface, that will then be removed through the machining process, ensuring  high metallurgical cleanliness.
  • Extremely rapid directional solidification of molten steel under the pressure generated by centrifugal force that results in  a very fine and defects free microstructure which produces outstanding mechanical properties and corrosion resistance.
  • High process versatility and the ability to produce small quantities ensures very short lead times.
  • Possibility to pour items with tailored chemical analysis.
  • Production of components difficult to be forged due to their poor cold or hot formability, with particular focus on heat resistant alloy products with high carbon levels.

Dimensional Range

Pipes with wall thicknesses from 10 to 150mm and lengths up to 5500mm. Rings, cones, flanges with wall thicknesses from 30 to 250mm. Balls with or without trunnions from 6″ to 32″.

Our products are supplied in rough condition or finished machined.

PRODUCTS

HORIZONTAL CENTRICAST ITEMS

Mechanical line pipes, line pipes for nuclear power stations, hydraulic or pneumatic cylinders, industrial gases production, conveyors rolls for pulp and paper, dairy, textile, printing, metallurgical  industries, bodies for HP ball valves,  rolls for heating furnaces, seats, rings, nozzles, radiant tubes, fittings for petrochemistry, assembled components.

Outer diameter from 80 to 1500mm, minimum internal diameter 45mm, unitary lengths up to 5500mm. Wall thicknesses from 10 to 150mm. Single piece weight up to 5000 kg.

VERTICAL CENTRICAST ITEMS

Balls and flanged bodies for HP valves, seat rings, cylindrical and shaped rings, flanged bushes, valves wedges, hydraulic cylinders and turbine seal and wear rings, seats, conical parts for centrifuges (rotors, bowl shells), valve cages, flanges, high pressure filter housings, conical parts for roll conveyors, gas turbine components, components for petrochemistry (tees, manifolds, line pipes).

Outer diameter from 280 to 1400mm, minimum internal diameters 115mm, lengths up to 1000mm. Wall thicknesses up to 250mm. Balls from 6″ to 32″, with or without trunnions. Single piece weight up to 4000 kg.

PIECES MANUFACTURED WITH DIFFERENT TECHNOLOGIES (SAND CASTINGS, CENTRIFUGAL CASTINGS) CAN BE WELD ASSEMBLED OBTAINING A WIDE RANGE OF PRODUCTS.

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Process and Plants

  • 1 Mould preparation
  • 2 Centrifugal casting
  • 3 Heat treatment
  • 4 Final inspections
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1. Mould preparation

Fondinox S.p.A. has the availability of a moulds warehouse that satisfies all dimensional needs. Moulds for horizontal and vertical centrifugal castings allow us to obtain products with dimensions near to finished products, minimizing cast weight and machining allowances.

After being selected, the  mould is placed on  a rotating centrifugal machine, preheated and covered with a refractory coating, ready for the pouring process.

2. Centrifugal casting

Centricast shop is equipped with four horizontal machines and four vertical machines to cover a wide production range. Molten metal is directly poured into the spinning metallic mould, where the very fast solidification process begins, guaranteed by the high thermal conductivity of the mould and by the water cooling. Once the solidification is completed, pieces are pulled off from the mould and ready for the structural treatment.

Steel mill is equipped with 10 medium frequency induction furnaces, with single capacities from 300 to 3500 kgs. The availability of so many furnaces allows us to work with the highest flexibility and to manage in the best way the wide variety of alloys that we produce.

3. Heat treatment

Heat treatment represents one of the most critical phases of the production process for special alloys. So Fondinox is equipped with 3 treatment furnaces that satisfy Norsok requirements up to 1250°C, with working zones up to 2.2×2.6×4.8m and pools up to 250m3 equipped with turbulent water recirculation units for rapid cooling of castings. Maximum working temperature of all our furnaces if 1430°C.

Solution annealing, water quenching, normalization, annealing, tempering and aging are performed on our steels and nickel alloys according to international specifications and following our internal procedures build up during our long experienced history.

4. Final inspections

Our technological internal laboratory is equipped to perform all tests according to international specifications: spectrometic chemical analysismechanical tests (tensile test, impact test, hardness, microhardness), corrosion test (intercrystalline, pitting, crevice, SSCC, SCC, HISC, accelerated corrosion),  metallographic analysis with optical microscopy and SEM. We are also equipped with Fischer FeriteScope and Thermo Scientific Niton XRF Analyzer for PMI.
VT performed on the entire production by our trained and highly skilled operators, PT carried out in a dedicated area with controlled environmental parameters.

Subcontracted European leader RT shop working under exclusive agreement equipped with 7 bunkers and 3 linear accelerators from 3, 6 and 9 MeV capable to test steel pieces with thicknesses up to 400mm. RT shop is located very near to our premises, leading us to operate with the maximum flexibility and rapidity on RT tests performed on our products.