METHOD FOR PREVENTING THE LEACHING OF COBALT AND NICKEL METAL SURFACES AND A CONCENTRATE USED IN SUCH METHOD

摘要

Metal working compositions (water base, oil base and oil-in-water-emulsions) containing a triazole of structure (I) in which R is hydrogen or methyl and/or a thiadiazole of structure (II) in which R is hydrogen or methyl and/or a thiadazole of structure (III) in which R sec is hydrogen, sodium or triethanol-ammonium. Optionally other additives may be added, e.g. sodium gluconate. The aqueous base and oil-in-water emulsions may be prepared in the form of a liquid concentrate which is subsequently diluted with water to form a metal working coolant or lubricant. These compositions prolong the life of metal cutting and grinding tools containing tungsten carbide particles bonded together by cobalt or nickel: .