Toroidal milling of hardened SAE H13 steel

Abstract

It is estimated that around 65% of the cost of a die or mould is related to the machining processes. Moreover, the literature says that 70% of the time spent in the machining processes of this kind of parts is used in finishing and semi-finishing operations. The high complexity of the machined surfaces makes mandatory the use of ball nose tools, with large overhang, what increases vibration in the process. These problems have to be minimized, since dies and moulds demand a very good surface finish and tight dimensional tolerances. A frequently used strategy to attenuate these problems is to carry out semi-finishing operations with cutters containing circular inserts, because these inserts produce smooth transitions among the passes and a smaller and more uniform stock material for the finishing operation. The main goal of this work is to evaluate the performance of rounded inserts of carbide and cermet in the semi-finishing milling (called toroidal milling) of H13 steel with hardness of 50 HRc. The influence of radial depth of cut, cutting speed and feed per tooth on tool life will also be considered. It also intends to test the feasibility of using minimum quantity of lubricant (MQL) technique instead of dry cutting in this kind of machining operation

Correlating surface roughness, tool wear and tool vibration in the milling process of hardened steel using long slender tools

“…According to Fallböhmer and Scurlock [34], cutting with a tool with a small level of wear may generate lower roughness than cutting with a fresh tool. Diniz et al [35] found similar results in the milling of H13 steel with a toroidal tool in semi-finishing conditions. A possible explanation for these results is that roughness values may be associated with tool coating defects on the cutting edge, as cited by Oliveira [13], which affect roughness at the beginning of tool life.…”

Surface Roughness Analysis in the Hard Milling of JIS SKD61 Alloy Steel

“…Under the optimized cutting conditions, the surface roughness was less than 0.25 µm. Diniz et al [4] achieved about 0.8 µm surface roughness value in the toroidal milling of hardened SAE H13. Karkalos et al [30] obtained 0.19 µm surface roughness value when milling Ti-6Al-4V ELI alloy.…”

“…The result of their research indicates that the surface roughness under the optimized cutting parameters is less 0.25 µm. Diniz et al [4] studied the toroidal milling of hardened SAE (Society of Automotive Engineers) H13 alloy steel using the minimum quantity of lubricant (MQL) technique. Their result indicates that the surface roughness value is 0.8 µm.…”

Multi-objective robust design of helical milling hole quality on AISI H13 hardened steel by normalized normal constraint coupled with robust parameter design

“…In this sense, molds and dies industry present important impact in the competitiveness of the forming processes. In a mold manufacturing it is estimated that 65% of the costs are due to finishing and semi-finishing processes by machining [2,3]. Between these processes, hole-making spends from 25% to 50% of the cycle time and 33% of the total number of operations, requesting reliability due to the high added value to the part being processed [4,5].…”