Development of a warm cross wedge rolling process using FEA and downsized experimental trials

Cross wedge rolling is a forming technology that offers a lot of advantages: No flash occurs, cycle times are low, lubricants are not necessary and the machines are easy to automate. Currently, cross wedge rolling is applied at hot temperatures only. An adaption of this technology to warm temperatures (about 500-950 degrees C) can increase the geometrical spectrum of warm forgings. The advantages of warm forged parts in comparison to hot forged parts are closer tolerances, reduced surface roughness, no scale and reduced decarburization. To apply cross wedge rolling at warm temperatures, the possibilities of defects e.g. internal voids and improper formed work pieces must be analysed. This paper describes the development of a warm cross wedge rolling process with one area reduction. The paper also includes results of finite element analysis (FEA), experimental trials with a downsized work piece and the adaption to the industrial work piece in original size. In the FEA simulations tools with serrations on the side have been used. The downsizing method is explained and the difference between FEA, downsized and originally sized work piece with the focus on forming forces, temperature distribution and defects are presented.