Manufacture and Performance of Spheroidal Graphite Cast lron Gears : 2nd Report, Load-carrying Capacities of As-cast FCD 70∼80 Gears

Abstract

A spheroidal graphite cast iron has many advantages in manufacturing and physical properties. The previous report showed that the new spheroidal graphite cast iron, which has high strength in as-cast condition, has a good machinability in hobbing tests and a high surface durability in roller tests. In order to apply this new material to medium-hardness gears, the load-carrying capacities are investigated by using a power circulating-type gear testing machine and a pulsator. the new spheroidal graphite cast iron gear has enough surface durability and tooth bending strength in comparison with alloy steel gears. In particular, the tooth surface of this material is smoother than that of alloy steel under the same hobbing conditions, and the material has a long pitting fatigue life. These facts indicate a typical availability of the new spheroidal graphite cast iron.