Effects of Austempering Process to Mechanical Properties of Thin Wall Ductile Iron Connecting Rod.

Abstract

Abstract Austempering process was carried out on thin wall ductile iron (TWDI) connecting rod produced by the design built in previous research. Austempering process was applied to improve the mechanical properties of the component, so it will be equal to forged steel. The aim of this work is to study the effects of austempering holding time to microstructure and mechanical properties of TWDI connecting rod. The process was applied to all connecting rods resulting from the vertical casting. The austenitising temperature was 960°C with 35 minutes holding time and the austempering temperature was 350°C with varied austempering holding time, that were 15, 30, 45 and 60 minutes. The process was held in fluidized bed furnace. Metallographic examination, tensile and compression stress-strain test were conducted directly to the connecting rod. The results showed that austempering process improved the mechanical properties of TWDI connecting rod and the result of the compression stress-strain test showed that the austempered TWDI connecting rod met its requirements.