Imparting high-temperature degradation resistance to metallic components
View Patent ↗A method of imparting high-temperature, degradation resistance to a metallic component involving applying a metal slurry comprising a Co-based metallic composition containing Co, Cr, Mo, Si, and B, a binder, and a solvent to a surface of the component, and sintering the Co-based metallic composition to form a substantially continuous Co-based alloy coating on the surface of the body.
1. A method of imparting high-temperature, degradation resistance to a metallic component comprising:
applying a metal slurry comprising solvent, binder, and metal particles of a Co-based alloy comprising between about 0.05 and about 0.5 wt % B, between about 5 and about 20 wt % Cr, between about 22 and 32 wt % Mo, between 1 and about 4 wt % Si, and balance Co to a surface of the metallic component, and wherein the metallic component has a body of a material selected from the group consisting of carbon steel, stainless steel, and alloy steel; and
heating to remove the solvent and binder and to sinter the Co-based alloy to form a substantially continuous Co-based alloy coating on the surface of the metallic component, wherein the Co-based alloy coating has a microstructure characterized by a generally non-dendritic, irregularly spherical, nodular intermetallic phase.
2. The method of claim 1 wherein the Co-based alloy consists essentially of between about 0.05 and about 0.5 wt % B, between about 5 and about 20 wt % Cr, between about 22 and 32 wt % Mo, between 1 and about 4 wt % Si, and balance Co.
3. The method of claim 2 wherein the Co-based alloy coating has a thickness between about 100 and about 300 microns.
4. The method of claim 2 wherein said sintering is performed at a temperature in the range of 2200° F. to 2300° F.
5. The method of claim 1 wherein said sintering is performed at a temperature in the range of 2200° F. to 2300° F.
6. The method of claim 5 wherein the Co-based alloy coating has a thickness between about 100 and about 300 microns.
7. The method of claim 1 wherein the Co-based alloy coating has a thickness between about 100 and about 1000 microns.
8. The method of claim 1 wherein the Co-based alloy coating has a thickness between about 100 and about 300 microns.
9. The method of claim 1 wherein the Co-based alloy coating has a thickness between about 250 and about 300 microns.
10. The method of claim 1 wherein the Co-based alloy comprises about B-0.15%, Cr-8.5%, Mo-28%, Si-2.6%, and balance Co.
11. The method of claim 1 wherein the metal slurry consists essentially of the metal particles, the binder, and the solvent, and wherein the metal particles are an alloy consisting essentially of about B-0.15%, Cr-8.5%, Mo-28%, Si-2.6%, and balance Co.
12. The method of claim 1 wherein the Co-based alloy comprises about B-0.15%, Cr-14%, Mo-26%, Si-2.6%, and balance Co.
13. The method of claim 1 wherein the metal slurry consists essentially of the metal particles, the binder, and the solvent, and wherein the metal particles are an alloy consisting essentially of about B-0.15%, Cr-14%, Mo-26%, Si-2.6%, and balance Co.
14. The method of claim 1 wherein the Co-based alloy comprises about B-0.15%, Cr-17%, Mo-28%, Si-3.25%, and balance Co.
15. The method of claim 1 wherein the metal slurry consists essentially of the metal particles, the binder, and the solvent, and wherein the metal particles are an alloy consisting essentially of about B-0.15%, Cr-17%, Mo-28%, Si-3.25%, and balance Co.
16. The method of claim 1 wherein the intermetallic phase is Laves phase nodules comprising dispersed particles and interconnected particles, wherein interconnections between particles include a plurality of thin filamentous Laves phase interconnections between dispersed Laves phase particles.
17. A method of imparting high-temperature, degradation resistance to a metallic component comprising:
applying a metal slurry comprising solvent, binder, and metal particles of an alloy consisting essentially of between about 0.05 and about 0.5 wt % B, between about 5 and about 20 wt % Cr, between about 22 and 32 wt % Mo, between 1 and about 4 wt % Si, and balance Co to a surface of the metallic component, and wherein the metallic component has a body of a material selected from the group consisting of carbon steel, stainless steel, and alloy steel; and
heating to remove the solvent and binder and to sinter the metal particles at a temperature in the range of 2200° F. to 2300° F. to form a substantially continuous Co-based alloy coating having a thickness between about 100 and about 1000 microns on the surface of the metallic component, wherein the Co-based alloy coating has a microstructure characterized by a generally non-dendritic, irregularly spherical, nodular intermetallic phase.