METHOD FOR REMOVING OXIDIZING LAYER ON SURFACE OF FE-NI SERIES ALLOY SHEET

摘要

PROBLEM TO BE SOLVED: To provide a removing method efficiently removing an oxidizing layer on the surface of an Fe-Ni series alloy hot rolled sheet and small in the loss of a base metal alloy. ;SOLUTION: An Fe-Ni series alloy sheet is subjected to immersing treatment with a mixed aq. soln. of 3 to 12 wt.% hydrochloric acid and 20 to 35 wt.% ferric chloride or is subjected to immersing treatment with an aq. soln. of 3 to 12 wt.% hydrochloric acid and is successively subjected to immersing treatment with an aq. soln. of 20 to 35 wt.% ferric chloride. In the above treatment, the concn. of hydrochloric acid is regulated to 5 to 10 wt.%, and the concn. of ferric chloride is regulated to 25 to 30 wt.%. Or, furthermore, the temp. of the aq. soln. is regulated to 60 to 80°C or the relative flow rate of the aq. soln. to the plane is regulated to 20 to 60 mpm. By using hydrochloric acid and ferric chloride having the above concns., an oxidizing layer on the surface of the Fe-Ni series alloy hot rolled sheet can be removed in a short time, and the loss of the base metal alloy can be reduced. It is preferable that the temp. is regulated to 60 to 80°C or the relative flow rate is regulated to 20 to 60 mpm from the viewpoint of the efficiency of descaling.;COPYRIGHT: (C)1998,JPO