Force Reduction in Bending of Thick Steel Plates by Localized Preheating

A trend towards higher tonnage press brakes, suitable for processing thick plates, can be observed. In this paper a dynamic method for preheating of thick steel plates, limited to the bending area, is presented, facilitating bending with a significantly reduced total force. The dynamic heating method thus allows to substantially extend the process window of press brakes. The method was experimentally tested on low carbon steel plates, characterised by a relatively high required temperature rise in order to achieve a favourable yield behaviour. A prototype setup developed for this purpose is described. Reported test results include achievable temperature distributions, force measurements as a function of temperature and spring back measurements. A derived simulation model allows to extrapolate the results to higher thickness plates.