Alloy coating for wet and high temperature pressing roll
AssigneeBeloit Technologies, Inc.
InventorJere W. Crouse
Life of this patent
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Abstract
A high temperature pressing roll has a cast or formed steel roll which is coated with a molybdenum-containing alloy. The preferred alloy has 14 to 16 percent molybdenum, 28 to 30 percent nickel, 30 to 34 percent chromium, 1.2 to 1.8 percent silicon, 4 to 4.5 percent boron, a maximum of 0.2 percent carbon and copper between 3 and 3.8 percent with the balance being iron. The roll is first coated with a bonding coating consisting of nickel and chromium. This bonding layer is then flame sprayed or plasma sprayed with a molybdenum alloy. The coating once applied is ground to a 30 RA or smoother surface. The molybdenum alloy is sprayed on to achieve a surface depth of approximately forty thousandths of an inch.
Claims1
A roll in a papermaking machine comprising;
- a roll formed of a first metal, said roll defining an outermost cylindrical surface;
- a metal alloy layer coated on said outermost cylindrical surface of the roll;
- said metal alloy layer consisting essentially of;
- 14 to 16 percent molybdenum;
- 28 to 30 percent nickel;
- 30 to 34 percent chromium;
- 1.2 to 1.8 percent silicon;
- 4 to 4.5 percent boron;
- 0.2 to 0 percent carbon;
- 3 to 3.8 percent copper;
- with the balance being iron;
- and
- said metal alloy inhibiting sticking of a paper web on said roll.
Dependencies are inferred from the claim text.