Optimization of the Mechanical Behaviour Under Tensile Stress of Spheroidal Cast Iron with Ferritic Matrix used in the Manufacture of Wind Turbine Hubs

Abstract

The aim of this study is the microstructural optimization of the toughness behaviour at sub-zero temperatures and the enhancement of the ductile behaviour under tensile stress of spheroidal graphite cast irons with a ferrite matrix used to manufacture hubs for horizontal axis wind turbines. The approach employed was a fractional design of experiments with 7 factors, 16 experiments and resolution IV. The research was conducted at an industrial scale on cubes with the same mass coefficient as that of the industrial parts to be enhanced. The main conclusion worth highlighting is that the use of nodulizers with traces of lanthanum enhances the toughness of the material at sub-zero temperatures and improves the ductility of these cast irons at the cost of lowering their yield strength. However, this negative effect may be offset by a decrease in the carbon equivalent to eutectic levels.