METHOD FOR DESCALING TITANIUM AND TITANIUM ALLOY MATERIAL

摘要

PURPOSE:To produce a product having a fine surface free from scale and reverse pits by spraying a mixed aqueous soln. contg. nitric acid and hydrofluoric acid each at a specified concn. on Ti or a Ti alloy having oxide scale. CONSTITUTION:A mixed aqueous soln. contg. >=170g/l HNO3 and >=17g/l HF is sprayed on the surface of Ti or a Ti alloy after continuous annealing so as to remove oxide scale on the surface. The temp. of the mixed aqueous soln. and the spraying time are not especially restricted unless incomplete descaling and over-pickling result. Thus, the metal can be descaled without forming reverse pits.