PURPOSE: To prevent economically the spalling of a rolling roll, in a wet skin- pass rolling, by adding an inhibitor having a corrosion-inhibiting effect for rolls and a material to be rolled to water and circulating the water.
CONSTITUTION: In dull finishing a galvernized steel sheet by a skin pass mill, the sheet is wet rolled while spraying water on rolls for preventing the dull surface from being clogged with powdery zinc. The water to be used for this purpose is adjusted to pH 8.0 on the base of Ca(OH)2 by adding an inhibitor consisting of 10ppm concentration sodium phosphate having corrosion-inhibiting effect against Fe, Zn, and is circulatingly used. Thus the generation of a roll spalling during wet rolling is prevented, and also the water circulation is profitable in the points of economy and environmental pollution.
NAKAI YOUICHI
TOTSUKA NOBUO
KURAHASHI HAYAO
