The structure design and cutting performance research about the groove of the indexable inserts for machining stainless steel

Abstract

Stainless steel as a widely used difficult-to-machine materials, difficult machining is mainly reflected in the chip hard to break, tool wear serious etc. A finishing indexable inserts designed and developed for stainless steel material. The tool is compared with commercial tools (NF4, BF) in terms of curved groove structure and cutting performance by SEM (scanning electron microscope, Sigma500), 3D scanning (KEYENCE-VR 5000) and profiler (Mitutoyo C-200). The developed HMF tool uses a curve edge with a curved chip breaker, and the tool nose has a chip breaking bump. The groove parameters of HMF indexable inserts are as follows：angle of cutting edge is 12°. chip breaker groove width is 1.89mm. Height of the back wall is 0.095mm. Anti-chip angle is 4°49'. 3D scanning of the chip break site reveals that the HMF chip break has a higher bump and a more pronounced chip rolling effect. HMF tool chip breaking experiments show that it has ideal chip breaking performance in the finishing range of ap=0.6 – 1.0mm, f=0.1 – 0.25mm/r. Chip analysis shows that the HMF chip curl frequency increases and the chip curl is tighter as the feed increases, and the curl radius gradually decreases when the feed is greater than 0.15mm/r. The results of the wear performance study are as follows: all three tools show rake face crater wear when cutting stainless steel. a small amount of built-up edge appears on the HMF cutting edge. the wear life of HMF is close to NF4 and better than BF. the wear of BF is faster in the later stages of wear.