Study Of Milling Performance For High-speed Milling Hardened Steel Mold Of High Hardness

The large cover mold of the car is the key technology of the automobile production, and its complex structural parts are mostly made using splicing hardened steel, which has a surface of the differential ratio hardness (hardnessHRC50-HRC65) in the milling area of hardened steel. What’s more, the amount of material removed is large during the processing, and the total utilization of the material is very low, which result in a growing proportion of total working hours in the processing. Therefore, we applied the high-speed cutting technology in such parts in order to improve a higher material removal rate on the blank,it has the reality significance to shorten the delivery cycle of parts and reduce production cost.In this paper,we made the high hardened mosaic mold steel materials of a variety of hardness Cr12MoV(HRC65, HRC60, HRC55, HRC50),7CrSiMnMoV(HRC65, HRC60, HRC55, HRC50) as research objects, choosing larger ball coated tools to made high-speed milling experiment.1.The different cutting parameters (milling speed, feed speed, axial cutting depth, radial cutting depth, tool overhang, tool milling direction) on milling force characteristics of the experiment are studied. We have made experiments on the mold materials of different hardness difference of the same hardness (small hardness and big hardness), the mold materials of different hardness difference of the different hardness (small hardness and big hardness), and have summarized the processing parameters for the typical mosaic hardened mold steel;2.The match performance of different coated tools (TiAIN, TiN, TiSiN, TiCN, TiAlSiN, Al2O3) and different processing phases in the milling process, the milling force, milling vibration, milling temperature, workpiece surface topography, surface quality and tool wear characteristics are studied. We optimized TiAIN coated tool as optimal cutting tool for high-speed cutting hardened steel mold of Cr12MoV (HRC65) in the finishing phase; While in the semi-finishing phase, for high speed cutting hardened steel mold Cr12MoV (HRC65), the optimal coated tool is TiAlSiN tool;3.The dynamic characteristics of high hardness hardened steel mold Cr12MoV (HRC65), stability factor in the milling process, the simulation of stability lobes diagram are studied. In the theoretical simulation model and the experimental conditions, based on the high hardness, we recommended cutting parameters for the selection of D=30mm ball tool machining hardened steel Cr12MoV(HRC65):n=10000rpm, Vc=942m/min, Vf=3000mm/min, ap=4.6mm, the optional processing parameters can better achieve high material removal rate and reduce the tool wear rate, extend tool life, in order to achieve efficient cutting.