BRASS ALLOYING METHOD BY THERMAL DIFFUSION

PURPOSE:To correct the characteristic of a plating liquid, plating current and diffusion voltage to the set values with respect to the prescribed beta bruss rate with high accuracy by measuring on-line and continuously the characteristic of the plating liquid, the coating weight of copper and zinc and the beta brass rate after the thermal diffusion treatment and controlling on-line and automatically the characteristic of the plating liquid, plating current and diffusion voltage. CONSTITUTION:A steel wire 1 is passed successively through a copper plating cell 6 and a zinc plating cell 7 and is thus plated with copper and zinc. The plated wire is passed through a diffusion soaking cell 10 and is subjected to brass alloying by the thermal diffusion treatment. The pH, temp., specific gravity, concn., etc. of the plating liquid are continuously measured by a fluorescent X-ray analysis device 15 and a measuring device 16 for the characteristic of the plating liquid in this stage and the coating weight of the copper and zinc on the steel wire 1 and the beta brass rate after the thermal diffusion treatment are on- line measured by an X-ray diffraction device 18. The characteristic of the plating liquid, plating current and diffusion voltage are thus on-line and automatically controlled and are corrected to the set values with respect to the prescribed beta brass rate with high accuracy.