PURPOSE: To strip easily oxide scale at a low cost by coating an aq. soln. of the halide of an alkali metal on the surface of a hot rolled stainless steel strip and subjecting the steel strip to annealing and cooling then to pickling.
CONSTITUTION: An aq. sodium chloride soln. is uniformly coated to a prescribed amt. on the surface of the hot rolled stainless steel and is subjected to a prescribed heat treatment in an annealing device. The oxide made on the surface of the rolled stainless steel strip is thereby further oxidized and is phase subjected to transition so that the steel strip surface has only the corundum type oxide. The corundum type oxide and the coefft. of thermal expansion of the steel strip has a considerable difference and therefore the corundum type oxide is cracked and is easily strippable. The projecting density of the shot blast and the conc. of sulfuric acid are thereby decreased in the stage of cooling the steel strip in the succeeding stage and descaling the same by shot blasting and pickling. Good surface condition is thus obtd.
WATANABE KENJI
YOSHIMOTO TAKESHI
SATO RYUZO
| JPS49135824A | 1974-12-27 |