A method is provided for removing iron oxide scale from sheet metal and producing a sheet metal surface with rust inhibitive properties. The sheet metal is advanced through the descaling cell and a slurry mixture is propelled 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. The rate of slurry impact against the at least one of the top surface and bottom surface of the sheet metal is controlled in a manner to remove substantially all of the scale from a surface of the sheet metal, and in a manner to create a passivation layer on the descaled surface of the sheet metal. The passivation layer comprises at least one of silicon, aluminum, manganese and chromium and inhibits oxidation of the descaled surface of the processed sheet metal.