SUMITOMO AC8000P steel turning selection and troubleshooting

Coating architecture of AC8020P/AC8025P/AC8035P

These three grades share four key designs, but have been differentiated for different operating conditions. The first layer is a special surface treatment layer that significantly improves the resistance to chipping and adhesion according to application requirements. AC8020P adopts pre compression processing to suppress blade breakage and improve visibility; AC8025P adopts smoothing treatment to suppress adhesion and chipping; AC8035P adopts pre compression treatment to suppress fracture. The second layer is a high-strength alumina layer, which significantly improves the coating strength by controlling the crystal growth direction. The third layer is a high hardness fine-grained TiCN layer, which significantly improves the hardness of the coating through a fine and uniform crystal structure. The fourth layer is high adhesion technology, which significantly improves the adhesion strength through a smooth coating and substrate interface.

In the intermittent cutting of 4137 steel forgings, AC8020P only showed slight damage after 400 impacts, continued after 1600 impacts, and only exhibited minimal chipping after 4000 impacts; However, conventional tools exhibit minor chipping after 400 impacts, and their lifespan ends after 1600 impacts. In the 8620 steel end face turning, the surface roughness of AC8025P is only Ra0.04 μ m, while conventional tools have Ra0.4 μ m; AC8025P only showed slight damage after 70 minutes and can continue after 120 minutes, while conventional tools showed adhesion after 70 minutes and subsequently broke. In the intermittent cutting of 4140 steel outer circle, the tensile residual stress of AC8035P was reduced by 90%, and all blade tips could still be used after 500 impacts, while conventional tools could not continue under the same impact times.

Decision Tree for Chip Groove Selection and Troubleshooting

The AC8000P series offers a wide range of chip breaker options, including EFE, ESE, ESU, EGE, EGU, EUX, EME, EMU, EMX, ELU, ESW, EEM, as well as heavy-duty machining EHW, EHP, EHG, EHF. Engineers can select models based on processing conditions and fault phenomena according to the following decision tree.

Main chip breaker: EGU and EGE

EGU is the universal preferred chip breaker, suitable for most steel turning conditions, with balanced chip control and wear resistance. EGE is suitable for medium cutting and can maintain stability even when increasing the feed rate. When the processing is stable and there are no special faults, EGU or EGE should be preferred.

Fault 1: Poor chip control or chip elongation

When chip elongation and poor chip breakage occur during small depth precision machining, choose EFE or ESE chip breaking groove. EFE is designed specifically for precision machining to small cutting depths, with excellent chip breaking ability at small cutting depths; ESE is suitable for efficient precision machining. If it is necessary to reduce cutting force at the same time, ELU or ESW chip breakers can be selected.

Fault 2: Broken blade or boundary defect

When there is damage caused by chipping, boundary defects, or impact loads during processing, choose AC8020P in conjunction with EGU or EGE chip breakers. If the blade breakage occurs under heavy intermittent working conditions, choose AC8035P in combination with EUX or EMU chip breaker. EUX has excellent anti chipping performance in stable cutting, while EMU is suitable for large depth rough machining.

Fault 3: Adhesion or chip accumulation tumor

When chip adhesion, chip accumulation or surface quality deterioration occurs during processing, choose AC8025P in combination with EGU or EGE chip breaker groove. Its surface smoothing treatment can significantly suppress adhesion and the resulting chipping. If adhesion occurs in precision machining conditions, ESU or ESE chip breakers can be selected.

Fault 4: Plastic deformation

When there is plastic deformation of the cutting edge, coating peeling, or rapid wear of the back cutting surface during processing, choose AC8115P in combination with EFE, ESE, or ESU chip breakers. The newly developed anti plastic deformation matrix can effectively resist plastic flow at high temperatures. If plastic deformation occurs during high-speed continuous machining, EME or EMU chip breakers can be selected.

Fault 5: Crescent wear and tear

When the crescent shaped groove is severely worn, choose AC8115P in combination with EME or EMU chip breaker. The crystal orientation control of the ultrafine alumina layer can significantly suppress crescent wear. If crescent wear occurs in general machining, AC8025P can be used in conjunction with EME or EMU chip breakers.

Summary of Recommended Cutting Parameters

According to the workpiece material and application conditions, the AC8000P series provides a recommended range of cutting conditions. The following is a summary of key materials.

Low carbon steel, low alloy steel (below 180HB)

For precision machining, it is recommended to use AC8115P in conjunction with EFE, with a cutting depth of 0.004-0.047 inches, a feed rate of 0.004-0.016 IPR, and a speed of 623-1640 SFM. General processing recommendation: AC8025P with EGU, cutting depth of 0.031-0.197 inches, feed rate of 0.004-0.018 IPR, speed of 492-984 SFM. For rough machining, it is recommended to use AC8020P with EMU, with a cutting depth of 0.071-0.236 inches, a feed rate of 0.008-0.024 IPR, and a speed of 459-1148 SFM. We recommend using AC8035P with EUX for heavy intermittent cutting, with a cutting depth of 0.031-0.197 inches, a feed rate of 0.006-0.018 IPR, and a speed of 328-820 SFM.