Highly shape-classified oxidized low carbon hypereutectoid electrostatographic steel carrier particles

Claim 1

A HIHGLY SHAPE-CLASSIFIED LOW CARBON HYPERECUTECTOID ELECTROSTATOGRAPHIC STEEL CARRIER MATERIAL HAVING AN AVERAGE PARTICLE SIZE BETWEEN ABOUT 50 MICRONS AND ABOUT 1,000 MICRONS AND SPECIFIC GRAVITY OF AT LEAST ABOUT 7 GRAMS PER CUBIC CENTIMETER WHEREIN SAID STEEL CARRIER MATERIAL HAS BEEN HEAT TREATED TO A TEMPERED MARTENSITIC MICROSTRUCTURE WITH AN AVERAGE HARDNESS OF 40-55 ROCKWELL C, SAID HEAT TREATMENT BEING IN AN AIR OR OXYGEN ATMOSPHERE AT TEMPERATURES RANGING BETWEEN ABOUT 500*F AND ABOUT 1,000*F TO PROVIDE AN OXIDE SURFACE LAYER COMPRISING FE3O4 ON SAID STEEL CARRIER MATERIAL, SAID OXIDE SURFACE LAYER HAVING A THICKNESS BETWEEN ABOUT 0.2 AND ABOUT 5.0 MICRONS, SAID STEEL CARRIER MATERIAL COMPRISING CARRIER CORES HAVING A COMPOSITION COMPRISING ABOUT 90.0 TO 99.0 PARTS IRON, 0.1 TO 2.0 PARTS CARBON, 0.5 TO 2.0 PARTS MANGANESE, 0.5 TO 2.0 PARTS SILICON, 0.03 TO 0.1 PARTS ALUMINUM, 0.01 TO 0.05 PARTS PHOSPHORUS, AND 0.02 TO 0.05 PARTS SULPHUR, SAID CARRIER CORES BEING OVERCOATED WITH A RESINOUS COATING MATERIAL CAPABLE OF ELECTROSTATICALLY RELEASING TONER PARTICLES ADHERED THERETO TO AN ELECTROSTATIC LATENT IMAGE.