Use of image processing to evaluate radial-axial rolled rings

Radial-axial rolled rings are produced in a hot forming process and the manufacturing still requires the use of allowances to ensure that the dimensions of the finished ring will be inside the given tolerances. To enable the production of near-net shape rings an evaluation of the rolled rings directly after the rolling process is necessary. For this evaluation a combination of image processing and thermal imaging to measure the diameter, the circularity and the surface temperature of rolled rings is pursued. This can help to initiate necessary changes regarding the final dimensions between two rings of the same lot. In this paper, the used imaging system will be briefly introduced and the approach to detect the outer diameter of rolled rings in warm condition as well as results of the image processing will be given and discussed. (C) 2014 The Authors. Published by Elsevier Ltd.