Heat treatment effects to the fracture splitting parameters of C70S6 connecting rod

Abstract

Crackable connecting rods have been widely used in cars' engines recently. In this method no machining is needed to seperate the connecting rod into two pieces. The main microstructure of the crackable C70S6 steel is pearlite (%90 of the structure is about pearlite). Changing the microstructure by various heat treatment applications can be economic and technologic alternatives to the use of crackable C70S6 steel. In this study, the effect of the bainitic microstructure of the crackable C70S6 steel is examined. Austempering has been applied to the crackable C70S6 steel and then fracture experiments has been carried out. It has been observed a perfect fracture surface. The hardness value of the fracture surface has been measured. Optical and SEM observations have showed us a perfect upper bainitic microstructure. It has been concluded that bainitic microstructure can be an important alternative to the convensional pearlitic crackable C70S6 connecting rods.