High strength constant velocity joint intermediate shaft

摘要

A steel material for a high strength constant velocity joint intermediate shaft containing C: 0.46 to 0.52%, Si: 0.6 to 0.8%, Mn: 0.7 to 0.9%, S: 0.01 to 0.05%, Mo: 0.3 to 0.5%, B: 0.0005 to 0.005%, Al: 0.002 to 0.05%, and Ti: 0.02 to 0.09%, restricting N to 0.007% or less, Cr to 0.15% or less, and P to 0.02% or less, having a structural percentage of bainite + martensite of 40% or more, and having a hardness of 250 to 340HV and a high strength constant velocity joint intermediate shaft made of that steel material, having a spline-vanishing part with a surface hardness of 610 to 750HV and a ratio t/r of an effective hardened layer d