Composite vertical metal and sand mould for casting rolls - where surface of metal mould is fed with cooling air, esp. to improve surface hardness of chilled cast iron roll barrel

摘要

A cylindrical metal or chilled mould (a) with a vertical axis is located between a bottom and top sand mould (b,c). Moulds (b,c) form the roll journals, whereas mould (a) forms the roll barrel. In the base of mould (a) is a circular row of radial channels employed to feed a coolant upwards along the bore of mould (a). An inlet channel and a ring distributor channel supply the coolant to the radial channels. All the coolant channels may be located in a separate ring forming the bottom part of mould (a); and mould (c) pref. contains vertical coolant exit channels closed by plugs which burn at 600-1000 deg. C below the casting temp. The chilled mould (a) is used to form a hard surface, esp. of white cast iron, on the roll barrel; and the coolant, e.g. air is used to reduce the total cooling time of the casting in the mould while also increasing the hardness of the white cast iron.