Prediction of the Surface Profile and Area of the Exit Cross Section of Workpiece in Round-Oval-Round Pass Sequence

抄録

In this paper, the model⁹⁾ that predicts the surface profile and area of exit cross section of workpiece in oval-round (or round-oval) pass rolling sequence has been improved. Afterward, the generality and robustness of the model was studied to assess the potential that finite element method generally used for predicting it might be replaced by the model. Since only the shape of the inlet cross-section of workpiece and geometry of the roll groove are considered in the model, the problem of obtaining the final rolled shape is greatly simplified and subsequently the computational time required for whole rolling process is a few seconds.
Extensive hot bar rolling experiments at different temperatures (800-1100°C) was carried out to investigate the effect of the change of rolling conditions and material parameters, such as the ratio of the specimen diameter to roll diameter, roll gap (i.e., pass height), roll groove design, steel grades and temperature of material on the model. This model has then been applied to a rod mill to extend its application coverage.
It was shown that the predicted surface profile and area of exit cross section are in good agreement with those experimentally measured for the variation of rolling conditions and material parameters. It was found that if we are interested in the capability for predicting the surface profile and area of exit cross section of workpiece for the entire rod (or bar) rolling line within a very short time, the proposed model might be an alternative which can replace the three-dimensional finite element method usually used in the analysis of rod(or bar) rolling analysis.