Relative Abrasiveness of the Cast Surfaces of Various Gray-Iron Castings on Single-Point Tools of High-Speed Steel

This study reveals that plain gray-iron castings made in sand molds have a very abrasive surface that results in a low tool life when machining the surface. This condition can be eliminated almost completely by pickling the castings prior to machining. Annealing improves the machinability of the casting, but it also results in a more pronounced “skin effect.” By means of an annealing and pickling treatment, the cutting speed for removing the surface was increased by 230 per cent.