Low-melting-point and little-scum hot dipping auxiliary plating agent

Abstract

The invention provides a low-melting-point and little-scum auxiliary hot dipping plating agent. The low-melting-point and little-scum hot dipping auxiliary plating agent is characterized in that: 1 liter of the auxiliary plating agent comprises 80 to 140 grams of zinc chloride, 10 to 30 grams of sodium chloride, 5 to 15 grams of sodium fluoride, 20 to 80 grams of dihydric phosphate, 0.2 to 3 grams of surfactant and the balance of water. The melting point of the auxiliary plating agent can be reduced to 142 to 223 DEG C, so a salt film is melted out easily during dip plating, the scum which isformed through a reaction of the auxiliary plating agent and zinc-based metal liquid is emerged quickly, smoke dust caused by the dip plating is reduced, the scum quantity is reduced, an interface substitution reaction between the interface of a plated metal piece matrix and the auxiliary plating agent salt film and the interface of the plated metal piece matrix and zinc-based alloy liquid is accelerated, the wettability of the auxiliary plating agent and the zinc-based metal liquid and a hot dip galvanizing production environment are improved, the plating omission or surface defects caused by the phenomenon that the scum is adhered to the surface of a plated part or floats to lag is avoided, auxiliary plating effect is improved, the plating omission rate is reduced, and the quality of plated parts is improved.

Description

technical field [0001] The invention relates to a plating flux, in particular to a plating flux with a low melting point, less scum, and no ammonia salt for hot-dip plating and a method for using the flux, which belongs to the technical field of metal material surface plating. Background technique [0002] The plating aid method in the traditional batch hot-dip plating process is to immerse the plated parts after pickling in a certain composition of zinc chloride-ammonium flux, take them out and dry or dry them after plating, that is, form on the surface of the plated parts. A film of zinc chloride-ammonium salt. The action mechanism of the flux is: to clean the dirt on the surface of the metal parts to be plated, to remove the iron salts or oxides remaining on the surface of the metal parts to be plated after pickling, and to prevent the metal parts to be plated from secondary oxidation in the air, so that The metal parts to be plated have greater surface activity when ent...

AI Technical Summary

Problems solved by technology

Because this type of flux is mainly composed of chloride salt as the main salt, the melting point of the double salt is above 240°C, which is about 10°C to 60°C higher than the melting point of the traditional zinc chloride-ammonium flux, resulting in solidification during immersion plating. / Liquid interface reaction lags behind, and the time for slag to float is delayed, which may easily cause missing plating and surface defects of the plated parts