Abstract
Body downsizing is required for high mileage and low pollution in the car and truck industry. In this situation, the substitution of cast iron with light alloy castings and design of castings for realizing thin-walled products are actively being promoted. The authors have developed a nodular cast iron with such casting properties as high strength and good elongation. We added 3mass% nickel to the general chemical composition of spheroidal graphite cast iron FCD450, and as a result, improved the matrix structure and mechanical properties without heat-treatment. The as-cast conditions of this material were ; tensile strength of 800MPa, 0.2% proof stress 530MPa, and 10% elongation. Furthermore, its machinability, a problem with high strength materials, was found to improve to the level of FCD600.
Using this material, we successfully reduced the weight of a truck suspension part by 42% compared to conventional products made of FCD500.
