Corrosion-resistant alloy and applications

Abstract

The present disclosure is directed to new ferritic alloys comprising iron, chromium, and silicon. The novel alloys have surprisingly enhanced corrosion resistant properties, with excellent workability, strength, and ductility. The disclosed alloys, and products made therefrom are useful in making low cost, efficient, and clean biomass stove combustors, as well as other devices for use with biomass fuel.

1 . An alloy comprising:
 about 13-17 wt % chromium (Cr);   about 2.0-3.5 wt % silicon (Si);   about 0.2-1.0 wt % manganese (Mn);   about 0.3-0.7 wt % titanium (Ti);   about 0.1-0.6 wt % carbon (C); and   wherein the remainder wt % is substantially iron (Fe).   
     
     
         2 . The alloy of  claim 1 , further comprising boron. 
     
     
         3 . The alloy of  claim 2 , wherein the boron concentration is between about 0.01 and 0.5 wt %. 
     
     
         4 . The alloy of  claim 3 , wherein the boron concentration is between about 0.05 to 0.15 wt. %. 
     
     
         5 . The alloy of  claim 4 , further comprising nickel. 
     
     
         6 . The alloy of  claim 5 , wherein the nickel concentration is between about 0.1 and 1.0 wt %. 
     
     
         7 . The alloy of  claim 6 , wherein the carbon concentration is between about 0.3 to 0.6C wt. %. 
     
     
         8 . The alloy of  claim 7 , wherein the carbon concentration is between about 0.4 to 0.6C wt. %. 
     
     
         9 . The alloy of  claim 5 , wherein the carbon concentration is between about 0.5 to 0.6C wt. %. 
     
     
         10 . The alloy of  claim 1 , wherein the alloy concentrations are about 15-16%% Cr, 2.4-2.6% Si, 0.4-0.6% Mn, 0.4-0.6% Ti, 0.5-6% C, and 78-82% Fe. 
     
     
         11 . The alloy of  claim 1 , wherein the alloy concentration is about 14-16% Cr, 2.4-3.2% Si, 0.4-0.6% Mn, 0.4-0.6% Ti, 0.4-0.6% C, and 78-82% Fe. 
     
     
         12 . The alloy of  claim 1 , wherein the alloy concentration is about 14-16% Cr, 2.4-3.2% Si, 0.4-0.6% Mn, 0.4-0.6% Ti, 0.3-0.6% C, and 78-82% Fe. 
     
     
         13 . A method of protecting a surface in a corrosive environment, the method comprising the steps of:
 providing a surface,   coating or constructing the surface with an alloy, the alloy comprising:
 about 13-17 wt % chromium (Cr); 
 about 2.0-3.5 wt % silicon (Si); 
 about 0.2-1.0 wt % manganese (Mn); 
 about 0.3-.0.7 wt % titanium (Ti); 
 about 0.1-0.6 wt % carbon (C); and 
 wherein the remainder wt % is substantially iron (Fe), 
   subjecting the coated surface to a corrosive environment, wherein the environment is at a temperature above about 400° C.   
     
     
         14 . The method of  claim 13 , wherein the alloy comprises all or part of a combustor of a stove. 
     
     
         15 . The method of  claim 14 , wherein the stove is a biomass stove. 
     
     
         16 . The method of  claim 13 , wherein the corrosive environment is a combustor of an energy conversion device. 
     
     
         17 . A method of producing an alloy product, the method comprising:
 heating the alloy to greater than about 1000° C.;   hot rolling the alloy to reduce its thickness by more than about 10%;   cooling the alloy to less than about 100° C.;   heating the alloy to greater than about 800° C.;   cooling the alloy to less than about 100° C.;   rolling the alloy to reduce its thickness by greater than about 50%; and   increasing the temperature of the alloy to greater than about 800° C.;   maintaining the increased temperature for at least about 5 min.   
     
     
         18 . The method of  claim 17 , wherein the alloy comprises about 13-17 wt % chromium (Cr); about 2.0-3.5 wt % silicon (Si); about 0.2-1.0 wt % manganese (Mn); about 0.3-0.7 wt % titanium (Ti); about 0.1-0.6 wt % carbon (C); and wherein the remainder wt % is substantially iron (Fe). 
     
     
         19 . The method of  claim 18 , wherein the alloy further comprises boron at a concentration between about 0.01 and 0.5 wt %. 
     
     
         20 . The method of  claim 19 , wherein the alloy further comprises nickel at a concentration between about 0.1 and 1.0 wt %.