To enable junction by which no chill is produced at a joint and to make a wheel support member lightweight by integrating a main body part made from nodular graphite cast iron and involving an arm part with a spindle part through friction pressure welding, the spindle part being made from a steel type material.
A knuckle spindle 1 serving as a wheel support member comprises a main body part 2, manufactured from nodular graphite cast iron and involving an arm part 5, and a spindle part 3 manufactured from a steel type material, which is joined to the main body part 2. At a friction pressure of 5 to 15Mpa and in a friction time of 30 to 60 seconds, the main body part 2 and the spindle part 3 are moved relative to each other while being rubbed against each other, after which upsetting is performed at an upset pressure of 20 to 60Mpa and in an upset time of 2 to 4 seconds to integrally join them 2, 3 together. Then no chill exists at the boundary of their junction, and junction of them can be performed well in a state approximating solid-phase welding.
YASUDA HISASHI
KOJO KATSUHIKO
OTSUKA KIMITERU
ITO YOSHITAKA
KADOTA SUSUMU
