Aqueous flux for hot dip galvanising process
AssigneeFoseco International Limited
InventorsMax Gerhard Neu, Arthur William Murcott
Life of this patent
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Abstract
Galvanising fluxes consisting of zinc chloride, one or more of sodium, potassium, calcium and magnesium chlorides, and an acid or acid salt (preferably aluminium chloride). In solution in water, the pH of the solution is less than 5.
Claims7
A galvanising flux solution which is a 3 to 30 percent by weight solution in water of a galvanising flux consisting essentially of
- i. at least 25 percent by weight of zinc chloride,
- ii. at least one chloride selected from the class consisting of sodium, potassium, calcium and magnesium chloride and
- iii. at least one acid salt which when dissolved in water at a concentration of 1.25 percent by weight give a solution having a pH of less than 5,
- the proportions and ingredients being such that when such a flux is placed in water at a concentration of 25 percent by weight, the pH of the solution is less than 5.
In the process of hot dip galvanising which comprises covering the surface of a ferrous metal article with a flux solution, optionally drying the article so as to leave a layer of flux on the surface of the article, immersing the article in molten zinc or zinc alloy, removing the article therefrom and allowing the molten zinc or zinc alloy on the surface of the article to solidify, the improvement which comprises using as flux solution an aqueous solution of a galvanising flux consisting essentially of
- i. at least 25 percent by weight of zinc chloride,
- ii. at least one chloride selected from the class consisting of sodium, potassium, calcium and magnesium chloride and
- iii. at least one acid salt which when dissolved in water at a concentration of 1.25 percent by weight give a solution having a pH of less than 5,
- the proportions and ingredients being such that when such a flux is placed in water at a concentration of 25 percent by weight, the pH of the solution is less than 5.
Dependencies are inferred from the claim text.