Relationship of microstructure on the mechanical and splitting fracture properties of a high carbon forging steel for connecting rod.

The influence of austenitizing temperature and isothermal transition temperature on the mechanical properties and splitting characteristics of C70S6 were investigated. The maximum ultimate tensile strength and yield strength were 1032 and 625 MPa, respectively, when the lamellar spacing of sorbite was 0.195 μm. The greatest elongation was 17% when the size of the pearlite colony was 13 μm, which suggested an approach for enhancing the properties of pearlite steel at a low cost. The splitting property performed excellent when the proeutectoid ferrite content is 0.3%, the prior austenite grain is 38.9 μm, and the yield ratio is 0.57 currently. The connection between the process performance and the microstructure parameters was established, allowing process improvement to be guided accurately. Highlights: A functional model exploiting the potential mechanical properties of F + P forging steels C70S6 was proposed.The combined action of less proeutectoid F and larger PAG could obtain better splitting characteristics.The connection between the process performance and the microstructure parameters was established. [ABSTRACT FROM AUTHOR]