Patent ID: 8128460

Claim:
A method comprising: providing a descaling cell for removing iron oxide scale from sheet metal, the sheet metal having top and bottom surfaces separated by a thickness of the sheet metal, and a length and a width, the sheet metal comprising iron, silicon, aluminum, manganese and chromium, the descaling cell comprising an enclosure with a generally hollow interior and an enclosure entrance opening and an enclosure exit opening, the descaling cell being adapted to receive the sheet metal through the enclosure entrance opening and advance the sheet metal through the enclosure and out the enclosure exit opening, the enclosure entrance and exit openings being sized to accommodate the sheet metal thickness and the sheet metal width, advancing the sheet metal through the descaling cell enclosure along a direction corresponding to the sheet metal length; in the enclosure hollow interior, propelling a slurry mixture against at least one of the top surface and bottom surface of the sheet metal across the sheet metal width as the material is advanced through the descaling cell wherein the slurry mixture is propelled against at least one of the top surface and the bottom surface of the sheet metal with a rotating impeller; controlling a rate of slurry impact against the at least one of the top surface and bottom surface of the sheet metal such that the slurry impact alone removes substantially all of the scale from a surface of the sheet metal, and creates a passivation layer on the descaled surface of the sheet metal, wherein the passivation layer comprises at least one of silicon, aluminum, manganese and chromium and wherein the passivation layer inhibits oxidation of the descaled surface of the sheet metal.