| 摘要 |
PURPOSE:To obtain magnetic iron powder of stable quality by easy operation by heat treating metallic iron particles or ferroalloy particles in a steam atmosphere at a specified temp. under a specified partial pressure of steam. CONSTITUTION:Metallic iron particles or iron-base ferroalloy particles are heat treated in a steam atmosphere at 200-600 deg.C under 0.01-<10% partial pressure of steam. By this treatment the surfaces of the iron particles are coated with iron oxide layers, and magnetic iron powder of stable quality useful as a magnetic recording material is obtd. When the powder is used in the manufacture of a magnetic tape, superior electromagnetic transducing characteristics, superior sensitivity and a low bias noise level are demonstrated. |
