PRODUCTION OF PURE TITANIUM SHEET EXCELLENT IN FORMABILITY AND SEIZURE RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a method for inexpensively producing a pure titanium sheet in which seizures are hard to occur at the time of working such as pressing and good in formability in pressing or the like. ;SOLUTION: A pure titanium material having a compsn. in which, by weight, the contents of Fe, Ni and Cr satisfy the inequalities I, II and III [the units are denoted by (ppm) in all cases] and the content of O (oxygen) is regulated to ≤900ppm, and the balance Ti with inevitable impurities is subjected to cold rolling and is next subjected to annealing treatment in the temp. range of 600 to 850°C to regulate the average grain diameter of 20 to 80μm, and after that, pickling treatment is executed with an aq. soln. of nitric-hydrofluoric acid satisfying the inequalities IV, V and VI (the units are denoted by weight% in all cases): the inequality I: 100≤Fe≤700, the inequality II: 100≤Ni+Cr≤700, the irnequality III: 200≤Fe+Ni+Cr≤1100, the inequality IV: 2≤hydrofluoric acid≤7, the inequality V: 4≤nitric acid≤20 and the inequality VI: I≤nitric acid/ hydrofluoric acid ≤5.;COPYRIGHT: (C)1998,JPO