Patent GB-1082605-A (GB)
Title: Treatment of metals
Inventor: RAVAULT FRANK ERNEST GEORGE
IPC: C03C4/00
Filed: 1965-01-22
Abstract: A composition for application to slabs, billets and other articles of metal such as tools prior to a heat treatment comprises ferrosilicon, silicon carbide, finely divided refractory material and a fusible glaze-forming material.  Oxidation and decarburization are thereby reduced.  Refractory materials specified are alumina, silica, magnesia or a silicate; the glaze-forming material may be powdered glass, or a mixture of silicates, borates or phosphates with metal oxides, e.g. iron oxide or lead oxide.  The composition may include a dispersing agent e.g. a montmorillonite gel; an adhesive substance e.g. a gum, resin or bentonite clay; ingredients which react together exothermically on heating such as an oxidizable substance e.g. a portion of the fero-silicon present, finely divided aluminium in which case a fluoride, examples of which are given, is also preferably added, and an oxidizing agent e.g. an alkali metal nitrate or chlorate an alkaline earth metal nitrate or chlorate, iron oxide, manganese dioxide or a mixture of any of these; and a slag-forming ingredient.  The composition in the form of a solution, dispersion or slurry in a liquid carrier e.g. water or an alcohol, may be applied by dipping, brushing, swabbing or spraying.  Preferred compositions contain silicon carbide 9-50%, ferrosilicon 6-60%, silicaflour 8-60% bentonite 2-10%, powdered glass 1-12%, sodium or potassium cryolite 1-15%, the percentages being by weight.ALSO:A composition for application to slabs, billets and other articles of metal such as tools prior to a heat treatment comprises ferro-silicon, silicon carbide, finely-divided refractory material and a fusible glaze-forming material. Oxidation and decarburization are thereby reduced.  Refractory materials specified are alumina, silica, magnesia or a silicate; the glaze-forming material may be powdered glass, or a mixture of silicates, borates or phosphates with metal oxides, e.g. iron oxide or lead oxide. The composition may include a dispersing agent, e.g. a montmorillonite gel; an adhesive substance, e.g. a gum, resin or bentonite clay: ingredients which react together exothermically on heating such as an oxidizable substance, e.g. a portion of the ferro-silicon present, finely-divided aluminium in which case a fluoride, examples of which are given is also preferably added, and an oxidizing agent, e.g. an alkali metal nitrate or chlorate an alkaline earth metal nitrate or chlorate, iron oxide, manganese dioxide or a mixture of any of these; and a slag-forming ingredient.  The composition in the form of a solution, dispersion or slurry in a liquid carrier, e.g. water or an alcohol, may be applied by dipping, brushing, swabbing or spraying.  Preferred compositions contain silicon carbide 9-50%, ferrosilicon 6-60%, silicaflour 8-60%, bentonite 2-10%, powdered glass 1-12%, sodium or potassium cryolite 1-15%, the percentages being by weight.ALSO:A composition for application to slabs, billets and other articles of metal such as tools prior to a heat treatment comprises ferrosilicon, silicon carbide, finely divided refractory material and a fusible glaze-forming material.  Oxidation and decarburization are thereby reduced.  Refractory materials specified are alumina, silica, magnesia or a silicate; the glaze-forming material may be powdered glass, or a mixture of silicates, borates or phosphates with metal oxides e.g. iron oxide or lead oxide.  The composition may include a dispersing agent, e.g. a montmorillonite gel; an adhesive substance e.g. a gum, resin or bentonite clay; ingredients which react together exothermically on heating such as an oxidisable substance, e.g. a portion of the fero-silicon present, finely divided aluminium in which case a fluoride, examples of which are given, is also preferably added, and an oxidizing agent, e.g. an alkali metal nitrate or chlorate, an alkaline earth metal nitrate or chlorate, iron oxide, manganese dioxide or a mixture of any of these; and a slag-forming ingredient.  The composition in the form of a solution, dispersion or slurry in a liquid carrier, e.g. water or an alcohol, may be applied by dipping, brushing, swabbing or spraying.  Preferred compositions contain silicon carbide 9-50%, ferrosilicon 6-60%, silicaflour 8-60%, bentonite 2-10%, powdered glass 1-12%, sodium or potassium cryolite 1-15%, the percentages being by weight.