Composite cast iron drier roll
AssigneeEutectic Corporation
InventorFrederick T. Jaeger
Life of this patent
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Abstract
A drier roll having a ferrous metal surface is provided with a surface coating of a hardfacing alloy, the ferrous metal surface having a thermal conductivity relative to silver taken as 1 cal/cm.sup.2 /cm/.degree. C/sec of at least about 0.06, the hardfacing alloy being a hardfacing heat, corrosion and wear resistant iron-group metal-base alloy mechanically and metallurgically bonded to said ferrous metal surface which is preferably made of cast iron, the hardfacing alloy coating having a thickness ranging from about 0.01 to 0.15 inch, the thermal conductivity of said coating being at least 0.05.
Claims11
A composite drier roll having a cylindrical ferrous metal surface with a primary hardfacing alloy coating mechanically and metallurgically bonded thereto,
- said ferrous metal substrate having a thermal conductivity relative to silver taken as 1 as substantially ambient temperature of at least about 0.06 calories/ sq.cm/cm/.degree. C/sec,
- said primary alloy coating being a flame sprayed heat, corrosion and wear resistant iron-group metal-base alloy having a thickness ranging from about 0.01 to 0.15 inch,
- said hardfacing alloy consisting essentially of a total of up to about 30% by weight of a strong boride and carbide-forming solute metal in amounts ranging from about 5% to 25% Cr, 0 to about 15% Mo, 0 to about 15% W, up to about 3% C, about 0.5% to 5% B, about 0.5% to 6% Si and the balance essentially said iron-group metal, the amount of boron or carbon present in said alloy being sufficient to combine with a substantial amount of said refractory metal to provide a mechanically and metallurgically bonded alloy coating having a thermal conductivity at substantially ambient temperature relative to silver taken as 1 of at least about 0.05 calories/ sq.cm/cm.degree. C.sec.
A composite drier roll having a cylindrical ferrous metal surface with a primary hardfacing alloy coating mechanically and metallurgically bonded thereto through an intermediate ductile metal cushion coating,
- said ferrous metal surface having a thermal conductivity relative to silver taken as 1 at substantially ambient temperature of at least about 0.06 calories/sq.cm/cm/.degree. C/sec,
- said primary alloy coating being a flame sprayed heat, corrosion and wear resistant iron-group metal-base alloy having a thickness ranging from about 0.01 to 0.15 inch,
- said hardfacing alloy consisting essentially of a total of up to about 30% by weight of a strong boride and carbideforming solute metal in amounts ranging from 5% to 25% Cr, 0 to about 15% Mo, 0 to about 15% W, up to about 3% C, about 0.5 to 5% B, about 0.5 to 6% Si and the balance essentially an iron-group metal, the amount of boron or carbon present in said alloy being sufficient to combine with a substantial amount of said refractory solute metal when present to provide a mechanically and metallurgically bonded alloy coating having a thermal conductivity at substantially ambient temperature relative to silver taken as 1 of at least about 0.05 calories/ sq.cm./cm/.degree. C/sec,
- said intermediate ductile metal cushion coating being selected from the group consisting of a ductile nickel-base alloy coating of thickness less than the primary coat and less than about 0.05 inch and a steel containing at least 95% iron and having a thickness ranging from about 0.01 to 0.13 inch.
Dependencies are inferred from the claim text.