| Abstract: | A comparison has been made of engineering steels produced by ingot and continuous casting. Particular attention has been paid to the possible influence of ghost lines, sometimes present in c.c. products, on the service behaviour of mechanical components. Experimentation has been concentrated on 40 CrMo 4 steel, used by an Italian automobile producer to make wheel hubs for motor-cars. The comparison has been carried out on the basis of tensile strength and ductility properties and low and high cycle fatigue behaviour. Rotating bending fatigue tests have also been conducted directly on wheel hubs, reproducing the main on-road fatigue conditions affecting these components. The experimentation has revealed no influence of ghost lines on the mechanical component behaviour and a complete tie-in between metallurgical characteristics and the static and dynamic properties of materials produced by the two steelmaking processes. |
