ROLLED MATERIAL FOR FRACTURE SPLIT CONNECTING ROD EXCELLING IN FRACTURE SPLITTABILITY, HOT FORGED PART FOR FRACTURE SPLIT CONNECTING ROD EXCELLING IN FRACTURE SPLITTABILITY, AND FRACTURE SPLIT CONNECTING ROD

摘要

A rolled material excelling in fracture splittability that is suitable for manufacturing of a connecting rod having its through-hole portion for assembly in crank shaft fracture split into roughly a semicircle. There is provided a rolled material satisfying a specified component requirement, exhibiting an average aspect ratio of sulfide inclusion, determined upon observation of D/4 portion (D: diameter of rolled material) in a section parallel to the longitudinal direction of rodlike rolled material, of 10.0 or below, exhibiting a value of Pc according to the following formula (1) of 0.41 to 0.75 and exhibiting a value of Veq according to the following formula (2) of 0.18 mass% or greater. Pc = C/(1-E/100) (1) {wherein C is the carbon content (mass%) of steel, and E is the ferrite fraction (area%)}, and Veq = V+Ti/2+Si/20 (2) {wherein V, Ti and Si are the contents (mass%) of relevant elements in steel}.