Finite Element Simulation on Face Milling of Austenitic Stainless Steel with Chamfered Tools

Due to the high strength of austenitic stainless steels, it is essential for cutting tool to keep with appropriate chamfered edges during the face milling process. In this paper, face milling mechanics with chamfered edge based on cutting force and chip formation were analyzed through finite element analysis (FEA). Three kinds of tools with different chamfered edges were studied on face milling of 1Cr18Ni9Ti austenitic stainless steel. The primary research results indicated that FEA results showed good consistency with experimental results. This can provide references for development and application of tools during face milling process.

Analytical and Thermal Modeling of High-Speed Machining With Chamfered Tools

High-speed machining offers several advantages such as increased flexibility and productivity for discrete-part manufacturing. However, excessive heat generation and resulting high temperatures on the tool and workpiece surfaces in high-speed machining leads to a shorter tool life and poor part quality, especially if the tool edge geometry and cutting conditions were not selected properly. In this study, analytical and thermal modeling of high-speed machining with chamfered tools in the presence of dead metal zone has been presented to investigate the effects of cutting conditions, heat generation, and resultant temperature distributions at the tool and in the workpiece. An analytical slip-line field model is utilized to investigate the process mechanics and friction at the tool-chip and tool-workpiece interfaces in the presence of the dead metal zone in machining with a negative rake chamfered polycrystalline cubic boron nitride tool. In order to identify friction conditions, a set of orthogonal cutting tests is performed on AISI 4340 steel and chip geometries and cutting forces are measured. Thermal modeling of machining with chamfered tools based on moving band heat source theory, which utilizes the identified friction conditions and stress distributions on the tool-chip and tool-workpiece interfaces, is also formulated and temperature distributions at the tool, cutting zone, and in the workpiece are obtained. These temperature distributions are compared with the results obtained from finite element simulations. The comparison of temperature fields indicates that the proposed model provides reasonable solutions to understand the mechanics of machining with chamfered tools. Models presented here can be further utilized to optimize the tool geometry and cutting conditions for increasing benefits that high-speed machining offers.

Effect of Different Edge Preparation on High Speed Turning Hardened Steel Process

Through combining turning experiments and FE simulations, this paper studied the effects of force, temperature and residual stress of machined surface on high speed hard turning GCr15 bearing steel hardened to HRC60-62 with three kinds of ordinary edge preparation (sharp-edge, hone and chamfer). The experiment and simulation results indicated that the diathermanous proportion of chamfered edge preparation to tool and machined surface is less, and this distribution of cutting temperatures is useful for tool life and machined surface quality. The simulation results showed that cutting force had a descending tendency with increasing of cutting speed, which is in accordance with the change rules of machining general rigidity material, and it proved that FE simulations have good precision. The simulation results of residual stress of machined surface showed that residual tensile stress existed in machined surface using both honed and chamfered tools, and a highest compressive stress (about -200MPa) existed among 150-200μm of the depth into the workpiece surface. The difference was that the depth of superficial harden layer with honed tools is larger than that with chamfered tools.