| High Manganese Steel(HMS) can be hardened and deformed by external shocks,then can show high strength, toughness, wear resistance, etc. Therefore HMS has been widely used in railway, military industry, construction machinery, mining machinery, etc. In cutting process, HMS is a typical difficult material which has also features of work hardening, the greater cutting force, the higher cutting temperature, etc. The contradiction between requirement of HMS and difficult process environments is increasingly prominent. For the difficult process of HMS a test of ultrasonic vibration turning ZGMnl3 steel was carried out by transforming lathe in order to improve machinability. The case of cutting force in ultrasonic vibration turning process is studied, the influence of typical factors on cutting force is analyzed and the empirical formula of cutting force is established.According to experimental needs, the ultrasonic vibration system is established. A suitable ultrasonic generator is chosen the size of ultrasonic transducer is calculated, a horn is designed after that modal analysis and harmonic response analysis of the horn are conducted; the impact of reactive load of quality on the performance of horn is studied. A special tool mounting for ultrasonic vibration cutting is designed. The experimental bench of ultrasonic vibration turning is built, and the optimal cutting condition is debugged.Through the contrast experiment in which ZGMn13 steel bar materials are machined by common turning and ultrasonic vibration turning method, surface state, cutting force and chip morphology are analyzed. Regularities and causes which the influence of several factors such as amplitude, cutting parameter,tool flank wear and tool material on main cutting force in ultrasonic vibration turning process are discussed. The orthogonal experiment research on cutting force in ultrasonic vibration turning HMS process is studied. Based on the arrangement of orthogonal regression design, the test data of main cutting forces which are with the change of amplitude and cutting parameter is obtained and the empirical formula of main cutting force is established. The good-of-fit test, regression equation test and regression coefficient test for the linear equation of main cutting force are conducted.The experiments have indicated that ultrasonic vibration turning is applied to HMS and cutting force is smaller than that of common turning, the empirical formula is accurate and reliable. The experimental results can play a definite part in directing cutting of HMS. |
PDF Full Text Request