Abstract: Disclosed is a paint composition of about 50 to about 95 wt % of a pigment, about 5 to about 50 wt % of a binder and sufficient solvent to give a solids content of about 30 to about 100 wt %. The pigment has two components--about 0 to about 90 wt % zinc and about 10 to about 100 wt % of a particular type of ferrophosphorus. The ferrophosphorus of this invention contains about 45 to about 63 wt % iron, about 20 to about 35 wt % phosphorus, about 2 to about 10 wt % vanadium, and about 1 to about 10 wt % chromium.

Abstract: A coating for improved resistance welding of galvanized steel parts or sheets comprises a binder, and a metal phosphide pigment, preferably a ferrophosphorus pigment, having a particle size of from about 0.1 to about 30 microns. The pigment can also include up to about 40% by weight of an additional metal such as tin, aluminum or lead, which can be combined with the metal phosphide in pigment form or deposited onto the surface of the particles. The coating can be applied to either the faying or non-faying surfaces of the galvanized steel, or to the resistance welding electrode, and may be removed, if desired, after the welding operation.The advantages of the present invention include a significant reduction in welding current and an increase in the weldability lobe width, a restoration of the dynamic resistance beta peak, and an increase in electrode life.

Abstract: A ferrophosphorous composition with improved conductivity and passivation resistance in prepared by treating ferrophosphorus particles with an aqueous solution containing a dilute mineral acid and ions of chromium and metal selected from the group consisting of zinc, strontium, calcium, barium, lead or copper. In a preferred embodiment, the concentration of chromium and zinc ions in the solution is in the range of about 2 grams/liter to about 10 grams/liter, and the treatment time is from about 2 to about 6 minutes.The treated ferrophosphorous particles can be formulated in a suitable resin binder for use as corrosion resistant coatings, weldable coatings, EMI shielding coatings or electrically conductive coatings. The treated ferrophosphorus particles can also be used in powder metallurgy applications.

Abstract: A coating for improved resistance welding of galvanized steel parts or sheets comprises a binder, and a metal phosphide pigment, preferably a ferrophosphorus pigment, having a particle size of from about 0.1 to about 30 microns. The pigment can also include up to about 40% by weight of an additional metal such as tin, aluminum or lead, which can be combined with the metal phosphide in pigment form or deposited onto the surface of the particles. The coating can be applied to either the faying or non-faying surfaces of the galvanized steel, or to the resistance welding electrode, and may be removed, if desired, after the welding operation.The advantages of the present invention include a significant reduction in welding current and an increase in the weldability lobe width, a restoration of the dynamic resistance beta peak, and an increase in electrode life.

Abstract: A ferrophosphorus composition with improved conductivity and passivation resistance is prepared by treating ferrophosphorus particles with an aqueous solution containing a dilute mineral acid and ions of chromium and a metal selected from the group consisting of zinc, strontium, calcium, barium, lead or copper. In a preferred embodiment, the concentration of chromium and zinc ions in the solution is in the range of about 2 grams/liter to about 10 grams/liter, and the treatment time is from about 2 to about 6 minutes.The treated ferrophosphorus particles can be formulated in a suitable resin binder for use as corrosion resistant coatings, weldable coatings, EMI shielding coatings or electrically conductive coatings. The treated ferrophosphorus particles can also be used in powder metallurgy applications.