Analysis and Control of Black Spots of Cold-rolled Titanium Coil

The occurrence of black spots of cold-rolled titanium coil was analyzed by scanning electron microscope. The results showed that the solid particles in the emulsion remained in the pits of the surface of titanium coil while rolling, which hadn't been eliminated by degreasing, and ofcer being annealed, the porticles caused the black spots of titanium coil after annealing. The ratio of black spots of cold-rolled titanium coil were significantly reduced after taking control measures.