FRICTION MODELING AND EXPERIMENTAL-OBSERVATIONS IN HOT RING COMPRESSION TESTS

Few studies have been undertaken to understand friction in hot metal f orming, especially when addressing the critical issue of whether chang ing magnitudes of strain rate and temperature at the interface influen ce the level of friction. This paper describes an experimental investi gation into friction under hot forming conditions using the ring compr ession test. The experiments shows how variations in temperature at th e interface affected the frictional behaviour. Additional observations were made with regard to the suitability of using the ring compressio n test for hot metal forming, especially their ability to reproduce pr ocess conditions in hot rolling. Finite-element simulations of the rin g compression test were also completed under similar temperatures as i n the experiments. The correlation between the experimental measuremen ts and the results of the process modelling is presented in the paper.