GB730931A - Improvements in or relating to methods of manufacturing slag-forming bodies for use in stud welding - Google Patents

Abstract

Slag-forming bodies for use in stud-welding comprise slag-forming constituents and metal particles coated with an oxide film. A pulverulent mixture of 30 per cent magnesium oxide, 25 per cent calcium fluoride, 35 per cent bentonite, and 10 per cent of a 55 per cent manganese-35 per cent silicon-10 per cent iron alloy is moulded with water to form a body which is degasified and sintered at 800 DEG C. in a furnace communicating with the air.ALSO:In making slag-forming bodies for stud welding in which a body containing metal particles and slag-forming constituents is heated to a high temperature for degasification and sintering, the particles are coated with an oxide film and the heating is performed in an oxidizing atmosphere. The film may consist of an oxide of silicon, chromium, aluminium or zirconium which may be provided by coating the particles with the material and then performing the heating step in the oxidizing atmosphere. Alternatively the metal of the particles, e.g. manganese is alloyed with a material providing a protective oxide film, e.g. silicon to form, e.g. a manganese 10 per cent silicon alloy. A pulverulent mixture of 30 per cent magnesium oxide, 25 per cent calcium fluoride, 35 per cent bentonite, 10 per cent of a 55 per cent manganese-35 per cent silicon-10 per cent iron alloy is moulded with water to form a body which is dried at 100 DEG C. and degasified and sintered at 800 DEG C. and in a furnace communicating with the air.