Mixed graphite cast iron for automotive exhaust component applications

Abstract

Both spheroidal graphite iron and compacted graphite iron are used in the automotive industry. A recently proposed mixed graphite iron exhibits a microstructure between the conventional spheroidal graphite iron and compacted graphite iron. Evaluation results clearly indicate the suitability and benefits of mixed graphite iron for exhaust component applications with respect to casting, machining, mechanical, thermophysical, oxidation, and thermal fatigue properties. A new ASTM standard specification (A1095) has been created for compacted, mixed, and spheroidal graphite silicon-molybdenum iron castings. This paper attempts to outline the latest progress in mixed graphite iron published.

Keywords

• SiMo iron
• spheroidal graphite
• compacted graphite
• mixed graphite
• exhaust components
• brittleness at medium temperature
• hermal fatigue cycles