Experimental evaluation of wear protection ability of sheet metal die covers in closed-die forging

Wear is the main mechanism that reduces the lifetime of forging dies used in closed die forging. A newly proposed approach to decrease die wear is the concept of protective sheet metal forging die covers, where an inexpensive and easy-to-exchange sheet metal die cover is used to protect forging dies. After this concept has been fundamentally validated by previous studies, the presented work aims to further evaluate the protective effects of this concept regarding wear reduction. First, an application-oriented experiment of the die cover concept on forging dies for producing square flange was conducted. On both the forging dies with and without die covers 100 forging strokes were carried out. The wear depths of both forging dies were then measured and compared. The results indicated that the forging die with die covers has up to 98% less wear than the forging die without die covers. The expected tool life of the forging die with die covers is therefore 600% longer. In addition, the die cover applied in the experiment achieved the service life of 100 forging cycles without being distorted, which reached the maximum service life of the die cover concept so far.