SHAPING A METAL WORKPIECE

摘要

A precoat composition including a particulate vitreous material and a particulate lubricant material (graphite and or boron nitride) dispersed in an organic medium comprising a solution of a polymeric binder is applied to the workpiece, and the workpiece is heated to a temperature (1000 to 1400 DEG F) sufficient to remove (538 to 760 DEG C) the organic medium and leave a residue of vitreous material and lubricant material on the workpiece. The workpiece is then inserted in a heated split die at 1350 to 1750 DEG F and the die loaded to alter the shape (752 DEG C to 960 DEG ) of the workpiece.… The ratio of the lubricant material to the vitreous material is at least 1:1 and the particle size of the lubricant material and the vitreous material is not more than 200 mesh (US Series), this being important for the surface quality of the shaped workpiece.