Towards a steady forming condition for radial–axial ring rolling

Cold ring rolling is an advanced but complex metal forming process under coupled effects with multi-factors, such as geometry sizes of rolls and ring blank, material, forming parameters, friction, etc. Investigating the plastic deformation behaviour (the plastic deformation state and its development) in the deformation zone during the process is very significant for rapidly predicting the metal flow, controlling the quality of deformed rings and optimizing the cold ring rolling process. In this paper, a decisive factor on plastic deformation behaviour, namely the average amount of feed per revolution , has firstly been ascertained. Then a functional relation, between and various process parameters, has been now established. Lastly, through 3D numerical simulation based on the elastic–plastic dynamic explicit FEM under the ABAQUS software environment, it has been found that there are three kinds of plastic deformation behaviours during cold ring rolling operation. One is that the material in the deformation zone entirely comes into the plastic deformation state at the early stage of the process. Two is that the material in the deformation zone gradually comes into the plastic deformation state during the process. And last is that at the end of the process, there is still a rigid zone in elastic deformation or small plastic strain state near the middle radius of the ring blank. Based on this, the influence of plastic deformation behaviours on metal flow, the degrees of inhomogeneous deformation of ring and force and power parameters in the cold ring rolling process have been explored. The achievements of this study thoroughly reveal the deformation mechanism of cold ring rolling and provide an important basis for the optimization of process parameters and precise control of the cold ring rolling process.

https://iopscience.iop.org/article/10.1088/0965-0393/13/7/002/pdf

Research on plastic deformation behaviour in cold ring rolling by FEM numerical simulation

Investigation of rolls size effects on hot ring rolling process by coupled thermo-mechanical 3D-FEA

Feed speed needs to be controlled during cold ring rolling but first it must be planned. However, up to now, it has been set mainly by trials and experience, as the existing method is inefficient. This paper aims to find a convenient method to plan feed speed. In this study, the ring outer diameter growth rate was regarded as the basic quantity to determine the feed speed. A mathematical model is built on analysis of the reason for the ring enlargement during rolling. The model defines the relationship between the ring outer diameter growth rate and feed speed. Using the model, the feed speed was planned versus the thickness of the rolling ring. The extrema of the feed speed and the ring outer diameter growth rate were also determined. The method of planning the feed speed based on the ring outer diameter growth rate is efficient and economical, and it facilitates process control for cold ring rolling.

Hua Lin

Papers

The extremum parameters in ring rolling