Coating material for metallic base material surface

Abstract

A spraying material for coating a metallic member, being inexpensive and having superior corrosion and erosion resistance even in high temperature environments, wherein the material is composed of an Fe—Si based compound and comprises an alloy composed of 10 to 35% by weight of Si and the remainder of Fe and inevitable impurities, and further, up to 5% by weight of B may be added to the material in terms of improvement in hardness and adhesiveness of the coating is provided in order to protect components such as heaters and water walls of coal fired boilers and heat exchanger tubes of fluidized bed boilers, etc., from corrosion and erosion. The spraying material is formed into a coating by, for example, high velocity flame spraying or atmospheric plasma spraying.

1 . A method for preparing a coating for a metallic base material surface, comprising an alloy composed of 19.82 to 35% by weight of Si and the remainder of Fe and inevitable impurities the method comprising,
 providing a coating composition comprising Si, and the remainder of Fe and inevitable impurities; and   spraying the coating composition onto the metallic base material surface by high velocity flame spraying or atmospheric plasma spraying.   
     
     
         2 . A method for preparing a coating for a metallic base material surface, comprising an alloy composed of 19.82 to 35% by weight of Si and the remainder of Fe and inevitable impurities the method comprising,
 providing a coating composition comprising Si, B and the remainder of Fe and inevitable impurities; and   spraying the coating composition onto the metallic base material surface by high velocity flame spraying or atmospheric plasma spraying.   
     
     
         3 . A method of coating a metallic base material surface, the method comprising:
 providing a coating composition, comprising a member selected from the group consisting of Fe 2 Si, Fe 5 Si 3  and FeSi; and   spraying the coating composition onto the metallic base material surface by high velocity flame spraying or atmospheric plasma spraying, wherein   the coating composition comprises an alloy composed of 19.82 to 35% by weight of Si, 1.02 to 5% by weight of B, and the remainder of Fe.