The ring rolling machine is mainly used for rolling bearing inner and outer rings, gear rings, pipe flanges, hubs, slewing supports, rotating wheel rings on lifting and transport machinery, reinforcing rings of large containers, and other forgings. It can roll carbon steel, stainless steel, titanium alloy, copper alloy, aluminium alloy, and high-temperature alloy ring pieces.
The ring rolling process starts with a circular preform of metal that has been previously upset and pierced (using the open die forging machines) to form a hollow "doughnut" This doughnut is heated above 1000? temperature and placed over the idler or mandrel roll. This idler roll then moves under pressure toward a drive roll that continuously rotates to reduce the wall thickness, thereby increasing the diameters (I.D. and O.D.) of the resulting ring.
Ring Rolling Process by Steps
- First is to heat the material to above 1000o C temperature.
- Starting stock cut to size by weight is first rounded, then upset to achieve structural integrity and directional grain flow.
- Piercing involves forcing a punch into the hot upset stock causing metal to be displaced radially, as shown by the illustration.
- A subsequent operation, shearing, serves to remove the small punch-out.
- producing a completed hole through the stock, which is now ready for the ring rolling operation itself. At this point the stock is called a preform.
- The doughnut-shaped preform is slipped over the ID roll shown here from an "above" view.
- A side view of the ring mill and preform workpiece, which squeezes it against the OD roll which imparts rotary action
- Resulting in a thinning of the section and correspondence increase in the diameter of the ring. Once off the ring mill, the ring is then ready for secondary operations such as close tolerance sizing, parting, heat treatment and test/inspection.
We manufacture Vertical Ring Rolling machines for the ring diameter of 75mm to 850mm, 500mm to 1000mm in China type Vertical design. And Radial-Axial (or Horizontal) Ring rolling machine for diameter upto 1250mm in R&D.