Patent ID: 6171657
Filing Date: 2001-01-09
Classification: C23C,D21F,F26B

Abstract:
A method of protectively coating against tribological and erosive wear a Yankee dryer drum useful in papermaking for drying a paper forming web, including interposing a drum coating on the surface of the Yankee dryer drum to be under said paper forming web, said drum coating comprising a thermally sprayed iron alloy composition selected from a set of possible compositions containing from about 20 to about 47 weight per cent chromium, about 2.5 to about 6.5 weight per cent boron, 0.0 to about 0.15 weight per cent carbon, about 1.7 to about 2.7 weight per cent silicon, less than about 8 weight per cent molybdenum, and the balance iron, said selected iron alloy composition establishing in said drum coating a characteristic Rockwell C hardness of approximately 55-70;whereby erosive wear of said drum dryer surface coated with said composition caused by chemical action of chloride, fluoride, and sulfite ions during papermaking is resisted.