Formability Issues in the Cold Extrusion of Rolled Rod

摘要

An automobile part manufacturing company is the leading supplier of metal-formed components to primary automobile manufacturers, capable of producing nearly 300 million precision cold forged parts per year. During the cold working of certain automotive drive components, 'end cracks' (Fig.1) were observed to occur randomly. As the name suggests, they are found on the front end of the part. These cracks are radial and they propagate in the longitudinal direction. They are visible to the naked eye, showing up after the extrusion stage or during subsequent machining operation. These cracks lead to significant economic losses due to large scrap volume and the requirement for inspection of each forged part once they are detected. Forging companies often resort to expensive processes like in-process annealing to reduce the probability of cracking.