THE SPEROIDIZATION GRAPHITIZATION CAST IRON, IN WHICH THE OUTER CIRCUMFERENCE IS TO THE DIFFERENT KIND STEEL MATERIAL THE CAST IRON CRANK AXLE AND CAST STEEL CRANK AXLE

摘要

Spheroidal graphite cast iron having an outer circumferential surface made of different type steel material and a cast steel crank axle is provided to improve rigidity and anti-abrasion property by melting different type steel and bonding the different type steel as an outer diameter member to a reinforced groove part. Spheroidal graphite cast iron having an outer circumferential surface made of different type steel material and a cast steel crank axle comprises a reinforced groove part(4). The reinforced groove part is formed in outer circumferential periphery of a crank shaft pin(1) and a crank shaft journal(2), and different type steel is inserted into the reinforced groove part as an outer diameter member(40) by melting and bonding. The reinforced groove part is provided inside with a stepped groove part(41).