| 摘要 |
1,226,328. Sintered metal coatings: Chromizing steel. ALBRIGHT & WILSON Ltd. Nov. 6, 1968 [Nov. 15, 1967], No. 52067/67. Headings C7D and C7F. A ferrous substrate such as a strip is chromized by depositing on to the substrate a Cr containing metal powder and one or more additional Al and/or Si containing powders which contain Al and/or Si in a proportion of not less than 40% by weight of any Cr present in the additional powder, the overall weight ratio of Cr to Al and/or Si in the deposited powders being from 1: to 99:1, compacting the powder layer, preferably coating with ferrous halide or another halide and then heating. The Al and/or Si powders are preferably ferro alloys containing 20-50% Al remainder Fe and at least 20% and preferably 50% Si and the remainder Fe. The Cr containing powder is preferably a Fe-Cr e. g. 82% Cr-18% Fe and all the powders are minus 100 mesh (BS). The powders may be applied to the substrate separately or as a blended mixture and compaction is effected by rolling. The compacted coated strip is then passed through a solution ferrous chloride and ammonium chloride, dried, coiled, and heated in H 2 at 800‹ -1000‹ C. |
