SUMITOMO AC8000P steel turning selection and troubleshooting

SUMITOMO AC8000P steel turning selection and troubleshooting

Steel turning is one of the most common processes in metal processing, but it is also the most prone to tool failure. From low carbon steel, high carbon steel to alloy steel, there are significant differences in hardness, toughness, and work hardening tendency among different materials. Engineers often face problems such as blade breakage, adhesion, crescent wear, back face wear, plastic deformation, and poor chip control. Faced with these faults, the AC8000P series coated hard alloy provides a complete solution from high-speed precision machining to heavy intermittent rough machining. This series includes four grades: AC8115P, AC8020P, AC8025P, and AC8035P, which are respectively designed for high-speed continuous processing, high-efficiency intermittent processing, universal processing, and heavy intermittent processing. This article will provide a systematic troubleshooting and selection guide from five dimensions: brand positioning, coating technology, chip breaker selection, recommended cutting parameters, and practical cases.

Brand positioning and troubleshooting logic

The core idea of the AC8000P series is to match different cutting conditions and failure modes through differentiated combinations of coating technology and substrate materials. Engineers can quickly identify suitable grades based on specific issues that arise during processing.

AC8115P: High speed continuous machining and resistance to plastic deformation

AC8115P is the preferred grade for high-speed machining, with a wear resistance of 1.5 times that of conventional tools and a plastic deformation resistance of over 2 times. When there is rapid wear of the back cutting surface, plastic deformation of the cutting edge, coating peeling or severe crescent wear during processing, AC8115P is the preferred choice. It is suitable for high-speed continuous turning, dry cutting, and precision machining of high hardness materials. The recommended chip breakers are EFE, ESE, and ESU, where EFE is used for small depth precision machining, ESE is used for efficient precision machining, and ESU is used for general precision machining.

AC8020P: Efficient Processing and Anti chipping Blade

AC8020P is positioned as an efficient processing grade, with anti chipping performance that is more than 2.5 times that of conventional tools. When cutting edge breakage, boundary defects, or damage caused by impact loads occur during processing, AC8020P can provide excellent stability. It is suitable for forging, intermittent cutting, and working conditions that require an increase in feed rate or cutting speed. Recommend EGE and EGU for chip breaking grooves. EGE is suitable for increasing feed rate, while EGU is suitable for increasing cutting speed.

AC8025P: Universal Processing and Anti Adhesion

AC8025P is the preferred recommended grade for general processing, with anti adhesion and anti chipping performance more than twice that of conventional tools. When chip adhesion, chip accumulation, surface quality deterioration, or slight chipping occur during processing, the surface smoothing treatment of AC8025P can significantly suppress adhesion and the resulting chipping. It is suitable for a wide range of working conditions from precision machining to rough machining, from continuous cutting to light intermittent cutting. The recommended chip breaker is EGU, which can also be paired with EFE, ESE, ESU, EGE, EUX, EME, EMU, EMX, etc.

AC8035P: Heavy intermittent machining and fracture resistance

AC8035P is positioned as an intermittent processing grade, with fracture resistance performance more than twice that of conventional tools. Its special surface treatment reduces the residual tensile stress in the coating, significantly suppressing crack propagation and fracture. When severe blade breakage, hot cracking, rapid fracture, or heavy intermittent impact damage occurs during processing, AC8035P is the preferred solution. It is suitable for heavy intermittent turning, unstable working conditions, and rough machining of high hardness materials. Recommended chip breakers are EGU and EUX. EGU is used to extend tool life, while EUX is used for stable cutting.

Analysis of Coating Technology

The reason why the AC8000P series can maintain stability under different working conditions lies in the collaborative design of coating technology and substrate materials.

Coating architecture of AC8115P

AC8115P adopts a four layer key design. The first layer is a hard surface layer that reduces initial wear while providing high compressive stress and a golden appearance, making it easy to identify the used blade tip angle. The second layer is a crystal orientation controlled ultrafine alumina layer, which improves the coating strength by controlling the crystal growth direction, suppresses wear caused by crystal detachment, and achieves wear resistance of more than 1.5 times that of conventional tools. 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 a newly developed hard alloy matrix that is resistant to plastic deformation. By improving its high-temperature performance, its ability to resist plastic deformation is more than doubled. In the external turning of 4137 steel, the wear of the rear cutting surface of AC8115P at 8 minutes is only 0.006 inches, while that of competitor A is 0.008 inches; In the dry cutting of W1-8 tool steel, conventional tools experience wear on the back cutting surface within 2 minutes due to plastic deformation, and even coating peeling occurs on competitor B, while AC8115P can continue processing after 4 minutes.

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.

High carbon steel, high alloy steel (above 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 459-1476 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 394-984 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 328-984 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 295-558 SFM.

Practical case verification

The following examples demonstrate the actual performance of the AC8000P series in different steel processing.

AC8115P case: 4140 rotor shaft and P110 tube

In the rough machining of the 4140 rotor shaft, TNMG433EMU-AC8115P tool was used with cutting parameters of vc=721 SFM, f=0.0157 IPR, ap=0.098 inches, wet cutting to suppress crescent wear and extend tool life by 1.3 times. In the processing of P110 tube, CNMG544EEM-AC8115P tool was used, with vc=607 SFM, f=0.0236 IPR, ap=0.157 inches. Under heavy load processing, the tool life was extended by 1.3 times. In another process of the 4140 rotor shaft, DNMG443EGE-AC8115P tool was used with vc=1017-1115 SFM, f=0.0157 IPR, ap=0.039-0.098 inches, resulting in a 2-fold extension of tool life. In the rough machining of the 1038 motor shaft, CNMG432EME-AC8115P tool with vc=919 SFM, f=0.0197 IPR, ap=0.079 inches was used to effectively suppress chipping and front face wear. In the processing of H13 mold, CNMG423EGE-AC8115P tool was used, with vc=394 SFM, f=0.0079 IPR, ap=0.059 inches, resulting in less wear under the same processing time.

AC8025P case: 1045 steel shaft end and 5115 steel ring gear

In the machining of the 1045 steel shaft end, CNMM434ENP-AC8025P cutting tool was used, with vc=590-655 SFM, f=0.017-0.022 IPR, ap=0.04-0.12 inches, and minimal wear on the crescent groove. A total of 150 pieces were machined. In the machining of 5115 steel ring gears, WNMG434EME-AC8025P tool with vc=820 SFM, f=0.012-0.018 IPR, ap=0.04-0.1 inches is used, and the tool life is extended by 1.5 times. In the processing of 4120 steel, DNMG442EEM-AC8025P cutting tool was used with vc=500 SFM, f=0.016 IPR, ap=0.16 inches, minimal damage, and 100 pieces were processed. In the processing of the soft steel front cover, TNMG332EFE-AC8025P cutting tool is used, with end face vc=1475-1575 SFM and inner hole vc=1310 SFM, extending the tool life by 1.3 times. In the processing of 4320 steel liner, CNMG434EME-AC8025P cutting tool was used, with vc=850 SFM, f=0.019-0.039 IPR, ap=0.06 inches, excellent wear on the back cutting surface, and 200 pieces were processed.

AC8035P case: 1035 steel planetary gear and hot-rolled steel flange

In the intermittent machining of 1035 steel planetary gears, CNMG433EUX-AC8035P tool was used, with vc=590 SFM, f=0.012 IPR, ap=0.080 inches, and the tool life was extended by 1.5 times. 300 pieces were machined, compared to only 200 pieces from competitors. In the intermittent processing of 1025 steel automotive parts, CNMG432EUX-AC8035P cutting tools were used with vc=330-425 SFM, f=0.008 IPR, ap=0.040-0.125 inches, resulting in minimal damage and processing of 120 pieces. In the rough and intermittent machining of hot-rolled steel flanges, TNMG332EGU-AC8035P cutting tool is used, with vc=330 SFM, f=0.012 IPR, ap=0.060 inches, and the tool life is extended by three times. In the machining of NiCr steel gears, WNMG432EUX-AC8035P tool is used, with vc=590 SFM, f=0.006-0.016 IPR, ap=0.040 inches, and the tool life is extended by 1.7 times. In the machining of 5120 steel reverse gear, WNMG432EUX-AC8035P tool with vc=755 SFM, f=0.006-0.012 IPR, ap=0.040-0.080 inches is used, and the tool life is extended by 1.6 times. In the processing of 5140 steel flanges, WNMG433EGU-AC8035P cutting tools were used, with vc=260-655 SFM, f=0.008 IPR, ap=0.040-0.060 inches, dry cutting, and tool life extended by 1.5 times. In the machining of alloy steel shaft ends, CNMG644EMU-AC8035P cutting tool is used, with vc=460-920 SFM, f=0.020 IPR, ap=0.195 inches, dry cutting, and the tool life is extended by 1.3 times.