Disclosed herein are refractory coating compositions with improved drying times, defect prevention, and gas permeability and methods for using such refractory coating compositions.

The present invention relates to a mould powder for coating cast moulds for reducing surface defects, such as pinholes, in ductile cast iron products. The mould powder comprises 10-99.5% by weight of a ferrosilicon alloy, 0.5-50% by weight of iron sulphide, and optionally 1-30% by weight of CaSi, and/or 1-10% by weight of CaF.sub.2. The invention further relates to a mould coating on and internal surface of a casting mould comprising 10-99.5% by weight of a ferrosilicon alloy, 0.5-50% by weight of iron sulphide, and optionally 1-30% by weight of CaSi, and/or 1-10% by weight of CaF.sub.2.

The invention relates to a rotary mold for centrifugal casting of an alloy. The mold comprises liners (135a) housed in hollow exoskeletons (137a). The exoskeletons retain the liners against the centrifugal force, during the casting, while the mold is spinning.

The invention concerns a unit comprising a mold (4) adapted to receive a molten metal alloy and the said metal alloy poured therein. The alloy is TiAl. The mold is rotational and comprises receiving recesses (135) made of steel, metal alloy and/or ceramic, and, at the location of a plurality of section planes each passing through the mold and the poured metal alloy, the mold has a surface heat capacity less than that of the poured metal alloy.

A description is given of the use of a refractory coating composition having a solids fraction of more than 69 wt %, based on the total mass of the coating composition, and also having a loss on ignition of less than 0.6 wt %, based on the total mass of the solids fraction of the coating composition, for producing a refractory coating on the inner walls of a centrifugal casting mold by means of a spray application. Further described is a method for producing a centrifugal casting mold provided on its inner walls with a refractory coating, for use in the centrifugal casting process, and also a method for producing a casting in the centrifugal casting process, preferably having a structured surface. Also described is a centrifugal casting mold for use in the centrifugal casting process, having a refractory coating on the inner walls of the centrifugal casting mold.

A method to make a tubular element to transfer abrasive materials such as concrete, inert materials or suchlike, where the tubular element includes an external tubular component made of steel and an internal tubular component, coaxial to the external tubular component, where the internal tubular component is made of chromium carbide, or other similar material resistant to wear.

A method to make a tubular element to transfer abrasive materials such as concrete, inert materials or suchlike, where the tubular element includes an external tubular component made of steel and an internal tubular component, coaxial to the external tubular component, where the internal tubular component is made of chromium carbide, or other similar material resistant to wear.

A metal mold for centrifugal casting, the exterior surface of which is provided with a coating in the form of an iron oxide film or a film containing calcium as the main ingredient. Such a coating is preferably formed so as to substantially cover the entire exterior surface. If the coating is an iron oxide film, it is preferable for the film to contain triiron tetraoxide. If the coating is a film containing calcium as the main ingredient, it is preferable for the thickness thereof to be at most 0.4 mm. Furthermore, among films containing calcium as the main ingredient, it is preferable for said main ingredient to be calcium carbonate. By configuring a mold for centrifugal casting in such a manner, the exterior surface of the metal mold can be uniformly cooled, and deformation of the mold can be suppressed.

The present invention relates to a mould powder for coating cast moulds for reducing surface defects, such as pinholes, in ductile cast iron products. The mould powder comprises 10-99.5% by weight of a ferrosilicon alloy, 0.5-50% by weight of iron sulphide, and optionally 1-30% by weight of CaSi, and/or 1-10% by weight of CaF.sub.2. The invention further relates to a mould coating on and internal surface of a casting mould comprising 10-99.5% by weight of a ferrosilicon alloy, 0.5-50% by weight of iron sulphide, and optionally 1-30% by weight of CaSi, and/or 1-10% by weight of CaF.sub.2.

A description is given of the use of a refractory coating composition having a solids fraction of more than 69 wt %, based on the total mass of the coating composition, and also having a loss on ignition of less than 0.6 wt %, based on the total mass of the solids fraction of the coating composition, for producing a refractory coating on the inner walls of a centrifugal casting mold by means of a spray application. Further described is a method for producing a centrifugal casting mold provided on its inner walls with a refractory coating, for use in the centrifugal casting process, and also a method for producing a casting in the centrifugal casting process, preferably having a structured surface. Also described is a centrifugal casting mold for use in the centrifugal casting process, having a refractory coating on the inner walls of the centrifugal casting mold.