WET TYPE SKINNPASS ROLLING METHOD OF COLD ROLLED STEEL SHEET FOR SURFACE TREATMENT

摘要

PURPOSE:To prevent jumping phenomena and make possible stable rolling by producing the cold rolled steel sheet for surface treatment from the steel blank whose C contents in steel are made specific amount or less and annealing the sheet then subjecting the same to wet type skin-pass rolling. CONSTITUTION:In the refining process of molten steel, C contents are kept 0.01% or less by using a vacuum degassing device or the like and the molten steel is made into a slab by ordinary ingot making and blooming or continuous casting. By using this slab, the slab is subjected to hot rolling and further pickling and cold rolling, whereby the cold rolled steel sheet for surface treatment is produced. When this cold rolled steel sheet is subjected to wet type skin-pass rolling after the annealing, the C amount contained in the steel and elongation unstable regions have a large correlation and the elongation unstable regions become 2% or less. Because of this, the sufficiently stable wet type skin pass rolling becomes possible.