Ring rolling

The Nature of Ring Rolling

Ring rolling – A forming process for Producing Seamless Rings

Ring rolling is a forming process for the production of rings. Commonly a headed and pierced ring is used as raw part to be expanded and possibly profiled with a ring rolling machine. Two or more rotating dies (rollers) are used for this purpose. By reducing the wall thickness and the height of the ring, the diameter of the ring increases while maintaining a constant volume. Profiled rollers enable the production of near net shape ring cross sections. The ring rolling processes enable the production of rings with diameters ranging from ten centimeters to ten meters. Though hot ring rolling is more common, cold rolling procedures have been deployed since the 1980s (e.g. for roller bearings or gear rings).

Ring rolling: Products and Target Industries

Typical Ring Rolling Products

Rolled rings are used in bearings, slewing bearings, turbine disks or in gear blanks. Wheel rolling machines produce solid wheels and wheel disks for high-speed trains, locomotives, railway carriages, trams and subway trains. Bevel gear and axle drive wheels for the automotive industry, transmission manufacturing, turbine manufacturing (e.g. turbine disks in plane propulsion engines), flanges in the machine and plant building industry, rings for tower flanges (in offshore wind turbines) and roller bearing manufacturing (cold rolling) are further examples of the diverse applications of ring rolling products.

 

Target Industries

Among the most important target industries are

  • Vehicle manufacturing / Automotive industry
  • Transportation industry
  • Aerospace industry
  • Machine and plant building industry
  • Offshore wind power and energy technology

 

Trends and Developments

Where is the development of ring rolling heading?

Ring rolling is trending towards new workpiece geometries and more complex component geometries (cross-section geometries for profiled rings) and ever-broadening product ranges, with expensive high-performance materials. For these reasons the practical knowledge gathered over decades by ring rolling specialists is insufficient to predict the interaction of different process parameters. Specialists are therefore relying on simulation software to model the ring rolling process and calculate material flow and material properties, assist in avoiding expensive faulty rolling errors, and facilitate process optimization. With the help of simulation, ring rolling processes can be brought close to technical maturity. Thus, not only are expensive and time consuming rolling trials substantially decreased in number, but the development of processes without prior practical experience becomes economically feasible.

3D Simulation of Ring Rolling Processes

Complex bulk forming processes such as ring rolling must be considered three dimensionally. At the same time, temperature development within the ring, especially when working with high-performance materials, substantially influences the process and the final properties of the materials used. Both factors pose high demands on the capabilities of the simulation software deployed. The usage of different grades and materials must also be taken into consideration. For the simulation of ring rolling processes, Simufact relies, among other things, on realistic elasto-plastic material modeling. This calculates the flow of material during rolling while taking into account the internal stress and the small, but due to the incremental forming very frequent spring back. The effect of friction between the workpiece and the driven or dragged rollers is included to enhance the precision of the simulated material flow. Furthermore, even the elasticity of the rollers and roll stands can be taken into account with minimal effort during modeling.

Typical Challenges When Ring Rolling

The art of ring rolling

App. Upsetting of a large ingot in a ring rolling plant (Source: Brück).
Upsetting of a large ingot in a ring rolling plant (Source: Brück).

When designing a ring rolling process, the geometry of the ring prior to rolling and the rolling strategy (i.e. the preform of the ring and the feeds and speeds of each roller) must be tuned in such a way as to reach the required final shape as optimally as possible. The rolling of profiled rings poses the additional challenge of attaining a complete and fold-free filled contour, while maintaining the correct diameter and wall thickness.

Furthermore, high-performance materials such as titanium and nickel based alloys can only be rolled successfully within a narrow range of temperatures.

What are your targets? Do you want to….

  • …Reach the highest geometric precision?
  • …Minimize the use of materials / resources?
  • …Stay within the “temperature window” for successful forming?
  • …Avoid rolling errors such as out-of-roundness, radial run-out, fold formation, cracks, fishtail formation, burr / flash formation, and incomplete filling of the profile?
  • …Avoid unstable processes?
  • …Stay within the load limits of your ring rolling machine?

All rolling errors have been simulated successfully with Simufact Forming.

A brief overview of Ring Roll Forging (FIA)

Our Solution for Ring Rolling

The Ring Rolling Module in Simufact Forming

The Simufact Forming Ring Rolling application module simulates ring rolling processes.

Whether ring rolling, ring expansion, axial rolling or wheel rolling, profiled rings or rings with rectangular cross-section, you can simulate all ring rolling processes in all dimensions and across the whole range of ring products. The software supports cold as well as hot rolling processes. The application module provides you with closed-loop controlled kinematics based on the ring growth.

 

Use the advantages of Simufact Forming for your ring rolling processes:

advantages:

  • Reduction of development times which leads to shorter time-to-market
  • Comprehensive understanding of the processes
  • Higher process stability and quality
  • Prediction of component properties
  • Better machine utilization
  • Expansion of the product range
  • Optimum adjustment of the different process stages
  • Higher yield
  • Avoidance of cracks

 

For a functional descriptions of Simufact Forming Ring Rolling, please refer to our product information.

Simufact Forming Ring Rolling