| 摘要 |
PURPOSE:To efficiently descale a cold rolled stainless steel strip by pickling the steel strip with a specified aqueous soln. contg. trichloroacetic acid and hydrochloric acid and by carrying out finish pickling with a specified aqueous soln. contg. nitric acid and hydrofluoric acid. CONSTITUTION:A cold rolled stainless steel strip is continuously pickled with an aqueous soln. contg. trichloroacetic acid and hydrochloric acid under conditions satisfying formulae CXH>=100, T1>=10 and 5<=t<=90 [where C is the concn. (%) of trichloroacetic acid expressed in terms of CCl4CO2H, H is the concn. (%) of hydrochloric acid expressed in terms of HCl, T1 is the temp. ( deg.C) of the aqueous soln., and t is immersion time (sec)]. Finish pickling is then carried out with an aqueous soln. contg. nitric acid and hydrofluoric acid under conditions satisfying formulae F>=0.05, 2<=N<=30 and 30<=T2<=80 [where F is the concn. (%) of hydrofluoric acid expressed in terms of HF, N is the concn. (%) of nitric acid expressed in terms of HNO3, and T2 is the temp. ( deg.C) of the aqueous soln.]. |
