Abstract
Manifolds made of cast iron are joined by melt welding, which however has the risks of causing partially chilled structures. In this study, lap joint friction stir welding of high silicon spheroidal graphite cast iron (high Si-FCD) and austenitic stainless steel (SUS) was investigated. In this process, the rotating stir rod is pushed into the lapped plates of SUS and high Si-FCD. The results showed that friction stir welding of high Si-FCD and SUS is possible regardless of the Si content, and that the area affected by heat spreads with increasing Si content. Microstructures of very fine ferrite were obtained at the high Si-FCD side by friction stir welding. In addition, joints free from chilled structure could be obtained by providing appropriate heat.
