Nippon Galvanizing Co., Ltd.

Yoichiro Suzuki

Takashi Nagao

Methods of improving the thickness and characteristics of galvanizing processes are disclosed. Several methods are disclosed which promote growth of the .zeta. layer in a double dipping galvanizing process. In one process a metal article is dipped in a molten-zinc bath at 430.degree.-480.degree. C. The article is then air-cooled or semi-air-cooled before it is dipped in a molten zinc bath containing no less than 0.1% aluminum at 390.degree.-460.degree. C. In another method, after molten-zinc-plating a metal article at 480.degree.-500.degree. C., the article is plated in a molten zinc bath containing no less than 0.1% of aluminum at 390.degree.-460.degree. C. In a third method, the surface of a metal article is blasted to form a surface having a roughness of at least 20 .mu.m before plating the article in a molten-zinc bath at 430.degree.-480.degree. C. The article is then plated in a molten zinc bath containing no less than 0.1% of aluminum at 390.degree.-450.degree. C.

Growing community of inventors

Mizunami, Japan

Yoichiro Suzuki