Ferrous camshaft prodn. in foundry mould - which has pinion and bearing cavities, the molten metal being differentially cooled in the cavities

摘要

A process for forming a ferrous camshaft having >=1 bearing lobe and >=1 pinion lobe, each having a predetermined carbon content, comprises forming a mould having >=1 cavity for the bearing lobe and for the pinion lobe and insulating selectively only the pinion lobe cavity from the mould. Molten ferrous metal is then cast into the mould whilst injecting into the mould a treatment agent before the mould is filled completely and cooling the molten metal in the mould at a predetermined speed, the metal contained in the bearing lobe cavity cooling at a different speed to that contained in the pinion lobe. The bearing and pinion lobes can be of a different hardness.