It is a special type of cogging process, in which cogging is done for surface hardening of the ring. In this video one can see the becking process setup. There is a ring which has to be surface hardened, the hammer translates up and down and beats up the ring at each stroke, roller rotates the ring to a certain angle at each stroke, this will be made, so that ring is equally beaten up at whole surface and the whole surface get hardened. At each stroke, a slight strain is produced at the surface of the ring. After each full revolution of the ring the same points are again beaten up by the hammer which will increase the equivalent strain further. In the image you can see the grain structure of the ring, it gets refined from initial stage to final stage of the ring and this make the ring surface hardened. The image also shows the dies used in the process. The hammer is shown with yellow color and roller is of green.