| 摘要 |
1,212,099. Making sintered ferrous lengths. JOHN SUMMERS & SONS Ltd. July 3, 1969 [July 18, 1968], No.34281/68. Heading C7D. Sintered ferrous lengths with at least one surface formed of stainless steel or iron is made by compacting ferrous powder through a first set of rolls, coating the length with Cr containing powder and rolling through a second set of rolls, applying a halogen containing solution to the length and then sintering e.g. in a reducing atmosphere. The length is preferably coiled prior to sintering and the halide solution may be an aqueous solution containing one or more of FeCl2, NH4Cl, NH4I, NaCl, NaF or a bromide. A slurry of Fe or steel powder with sodium carboxy methyl cellulose and optionally Ni powder and Fe/Cr is cast, dried and rolled, optionally heated at 800‹ C., melted with sodium or potassium silicate, sodium carboxy methyl cellulose, Ni(OH)2 or Al(OH)3 and electrostatically coated with Cr. After rolling, the halide is applied and sintering is effected. Fe/Cr, Ni, Ti, Mo, Al, V and Si may be added with the Cr powder. Ni may alternatively be electro-plated on the rolled ferrous length prior to applying the Cr. |
