Molding machine cylinder and its production method
AssigneeHitachi Metals, Ltd.
InventorsMasatsugu Uchida, Kiyoshi Furushima
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Abstract
A molding machine cylinder comprising a lining layer having a structure comprising 20-50% by area of tungsten carbide particles and 1-10% by area of tungsten-based metal carboboride particles in a nickel-based alloy matrix, and containing 1-7.5% by mass of Fe, can be produced by a centrifugal casting method comprising a first step of heating at higher than 1140° C. and lower than 1200° C., and a second step of heating at 1080-1140° C. after melting the raw material powder.
Claims4
A method for producing a molding machine cylinder comprising a lining layer having a structure comprising 20-50% by area of tungsten carbide particles and 1-10% by area of tungsten-based metal carboboride particles in a nickel-based alloy matrix, the % by area being based on a cross section of the lining layer, and containing 1-7.5% by mass of Fe, comprising the steps of
- charging a raw material for the lining layer into a steel cylinder, said raw material comprising 40-70 parts by mass of nickel-based alloy powder containing 1-5% by mass of B, and 60-30 parts by mass of tungsten carbide powder;
- melting said raw material for the lining layer while rotating said cylinder at 5-30 rpm;
- increasing the number of rotation of said cylinder for centrifugal casting, to form a centrifugally cast layer comprising an outside lining layer and an inside particle-lack layer on an inner surface of said cylinder;
- and
- removing said particle-lack layer by machining;
- said raw material for the lining layer being melted by a first step of heating at higher than 1140° C. and lower than 1200° C., and a second step of heating at 1080-1140° C. after said first heating step.
Dependencies are inferred from the claim text.