Thermal spray coated work rolls for use in metal and metal alloy sheet manufacture

A work roll for use in metal or metal alloy sheet manufacture comprising a cylindrical-like structure having an outer peripheral surface and a thermally sprayed coating on the outer peripheral surface of said cylindrical-like structure, wherein said thermally sprayed coating is thermal sprayed from a thermal spray powder, said thermally sprayed coating comprising (i) one or more metal carbides represented by the formula MxC wherein M is one or more of W, Co, Mo and Cr, (ii) a metallic binder comprising Co, Cr, Mn, Fe, and/or Ni, and (iii) a Cr2O3 layer in at least a portion of splat boundaries to protect said metal carbides and said metallic binder;

• wherein said thermal spray powder has a particle size from about 5 to about 50 microns and a metal carbide grain size of from about 0.1 to about 2 microns;
• and wherein said thermally sprayed coating has a surface roughness less than about 60 microinches Ra;
• wherein MxC comprises one or more of MC, M2C M6C, M9C and M12C phases;
• and wherein said thermally sprayed coating has a porosity of not greater than about 2.5%.

A work roll for use in metal or metal alloy sheet manufacture comprising a cylindrical-like structure having an outer peripheral surface and a thermally sprayed coating on the outer peripheral surface of said cylindrical-like structure, wherein said thermally sprayed coating is thermal sprayed from a thermal spray powder, said thermally sprayed coating comprising (i) one or more metal carbides represented by the formula MxC wherein M is one or more of W, Co, Mo and Cr, (ii) a metallic binder comprising Co, Cr, Mn, Fe, and/or Ni, and (iii) a Cr2O3 layer in at least a portion of splat boundaries to protect said metal carbides and said metallic binder;

• wherein said thermal spray powder has a particle size from about 5 to about 50 microns, a cobalt particle size of from about 0.1 to about 10 microns, and a metal carbide grain size of from about 0.1 to about 2 microns;
• and wherein said thermally sprayed coating has a surface roughness less than about 60 microinches Ra;
• wherein Mxcomprises one or more of MC, M2C, M6C, M9C and M12C phases;
• and wherein said thermally sprayed coating has a porosity of not greater than about 2.5%.

A work roll for use in metal or metal alloy sheet manufacture, said work roll comprising a cylindrical-like structure having an outer peripheral surface and a thermally sprayed coating on the outer peripheral surface of said cylindrical-like structure, wherein said thermally sprayed coating is thermal sprayed from a thermal spray powder, said thermally sprayed coating comprising from about 65 to about 95 weight percent of one or more metal carbides represented by the formula MxC wherein M is one or more of W, Co, Mo and Cr, and from about 5 to about 35 weight percent of one or more transition metals selected from chromium, manganese, iron, cobalt and nickel;

• wherein said thermal spray powder has a particle size from about 5 to about 50 microns and a Group VI metal carbide grain size of from about 0.1 to about 5 microns;
• wherein said thermally sprayed coating has a surface roughness less than about 60 microinches Ra;
• wherein MxC comprises one or more of MC, M2C, M6C, M9C and M12C phases;
• wherein said thermally sprayed coating has a porosity of not greater than about 2.5%;
• and wherein said thermally sprayed coating increases the time required for reduction forces to wear said thermally sprayed coating and damage surface quality of the metal or metal alloy sheet.

A work roll for use in metal or metal alloy sheet manufacture comprising a cylindrical-like structure having an outer peripheral surface and a thermally sprayed coating on the outer peripheral surface of said cylindrical-like structure, wherein said thermally sprayed coating is thermal sprayed from a thermal spray powder, said thermally sprayed coating comprising (i) one or more metal carbides represented by the formula MxC wherein M is one or more of W, Co, Mo and Cr, (ii) a metallic binder comprising Co, Cr, Mn, Fe, and/or Ni, and (iii) a Cr2O3 layer in at least a portion of splat boundaries to protect said metal carbides and said metallic binder;

• wherein said thermal spray powder has a particle size from about 5 to about 50 microns and a metal carbide grain size of from about 0.1 to about 5 microns;
• wherein said thermally sprayed coating has a surface roughness less than about 60 microinches Ra;
• wherein MxC comprises one or more of MC, M2C, M6C, M9C, and M12C phases;
• wherein said thermally sprayed coating has a porosity of not greater than about 2.5%;
• and wherein said thermally sprayed coating increases the time required for reduction forces to wear said thermally sprayed coating and damage surface quality of the metal or metal alloy sheet.

A work roll for use in metal or metal alloy sheet manufacture comprising a cylindrical-like structure having an outer peripheral surface and a thermally sprayed coating on the outer peripheral surface of said cylindrical-like structure, wherein said thermally sprayed coating is thermal sprayed from a thermal spray powder, said thermally sprayed coating comprising (i) one or more metal carbides represented by the formula MxC wherein M is one or more of W, Co, Mo and Cr, (ii) a metallic binder comprising Co, Cr, Mn, Fe, and/or Ni, and (iii) a Cr2O3 layer in at least a portion of splat boundaries to protect said metal carbides and said metallic binder;

• wherein said thermal spray powder has a particle size from about 5 to about 50 microns, a cobalt particle size of from about 0.1 to about 10 microns, and a metal carbide grain size of from about 0.1 to about 5 microns;
• wherein said thermally sprayed coating has a surface roughness less than about 60 microinches Ra;
• wherein MxC comprises one or more of MC, M2C M6C M9C and M12C phases;
• wherein said thermally sprayed coating has a porosity of not greater than about 2.5%;
• and wherein said thermally sprayed coating increases the time required for reduction forces to wear said thermally sprayed coating and damage surface quality of the metal or metal alloy sheet.