METHOD AND APPARATUS FOR MELT PLATING

摘要

A batchwise method of melt plating in which, prior to immersing a metal material in a melt plating bath, the metal material is immersed in a molten salt flux bath (e.g., quartz + at least one kind of alkali metal chloride and, optionally, aluminum fluoride) having a melting point higher by at least 5 DEG C than the temperature of the plating bath, treated with the flux which also serves as pre-heating, and is then quickly immersed in the plating bath. Failure of plating is reliably prevented when the molten metal material is an Al-Zn alloy and, particularly, is a Zn - 55 % Al - 0.5 to 2 % Si alloy. No treatment is required for removing the flux, and a plated film of good appearance is formed by the immersion for a short period of time. The life of the plating vessel can be strikingly lengthened when the plating vessel has a round sectional shape such as a semicircular shape or a laterally elongated semi-oval shape instead of a box shape.