Process Condition Diagram Predicting Onset of Microdefects and Fracture in Cold Bar Drawing

This paper presents a process condition diagram (PCD) that not only identifies conditions under which materials fracture during bar drawing, but also infers the presence or absence of microdefects such as microvoids and microcracks in drawn material accumulative damage changes owing to die semi-angle reduction ratio. The values were calculated by finite element (FE) analysis. critical determined performing tensile test using smooth round specimen FE analysis simulating test. High alloy steel with 13 mm diameter was used for draw bench testing wide range drawing conditions. Scanning electron microscopy (SEM) performed verify usefulness PCD. SEM images showed roughly matched size around non-metallic inclusions creation microcracks, eventually led fractures being drawn. Hence, utilizing proposed PCD, designer can design minimize occurrence while maximizing