Influence of Ghost Lines on the Performance of Continuously Cast Special Structural Steels

Abstract

An assessment was made of the in-use performance of special structural steels produced by the ingot and the continuous casting (c.c.) process. Particular attention has been paied to the influence of the ghost lines occasionally observed in c. c. products on the behaviour of mechanical components. Steel 40CrMo4 used by Fiat Auto for the manufacture of car front wheel hubs was studied in terms of its strength, ductility, low and high cycle fatigue resistence. Rotating bending fatigue tests were also performed on wheel hubs under simulated on-road conditions. A complete correspondence was observed between the metallurgical, static and dynamic properties of the steel produced by the two fabrication processes.