Effect of Annealing Conditions on Gloss of Pickled Pure Titanium for Construction Service

The effect of oxygen concentration in the furnace and annealing time on the gloss of pickled pure titanium was studied to stabilize the gloss of pure titanium for construction manufactured by the continuous annealing and pickling line (APL).The gloss of pickled pure titanium annealed in 3% O2 was lower than that annealed in 5% or 10% O2. When the oxygen concentration was low, fine scale formed that was difficult to remove by dipping in a molten salt bath and thus difficult to pickle, lowering gross. Gloss was low when annealing time was short, and grain growth did not occur sufficiently, increasing the number of peaks of pickled pure titanium on the surface. Applying these findings to APL operation made it possible to control precisely the gloss of pure titanium for construction.