SUMITOMO AC6000M Stainless Steel Turning Guide

SUMITOMO AC6000M Stainless Steel Turning Guide

Stainless steel turning has always been a challenging step in metal processing. Whether it is austenitic, martensitic, ferritic, or duplex stainless steel, problems such as adhesion, chipping, crescent wear, flank wear, work hardening, and poor chip control may occur during the machining process. Faced with these faults, engineers often need to make a trade-off between wear resistance and resistance to chipping. The AC6000M series coated hard alloy is a complete product line designed to solve this contradiction, including four grades: AC6020M, AC6030M, AC6135M, and AC6145M, covering precision machining, continuous machining, light intermittent machining, and heavy intermittent machining, respectively. 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 AC6000M series is to match different cutting conditions and fault modes through a differentiated combination of CVD and PVD coating technologies.

AC6020M: The preferred choice for precision machining and high-speed machining

AC6020M adopts a combination of CVD coating and high hardness hard alloy substrate, providing stable and long tool life in precision machining and high-speed machining. When problems such as rapid wear of the rear cutting edge, insufficient sharpness of the cutting edge, and decreased surface quality occur during processing, AC6020M is the preferred choice. It is suitable for continuous cutting and light intermittent cutting, especially in precision machining of ferritic stainless steel, martensitic stainless steel, and precipitation hardened stainless steel. The recommended chip breakers are EEF and ESU, with EEF emphasizing chip control and ESU emphasizing suppression of cutting forces.

AC6030M: Preferred recommendation for continuous cutting

AC6030M is the preferred recommended grade for continuous cutting, and its CVD coating significantly reduces common abnormal damage in stainless steel processing, achieving long-term stable tool life. When the machining condition is continuous turning and the main faults are crescent wear, wear on the back cutting surface, or surface quality deterioration caused by adhesion, AC6030M is the best choice. It is suitable for continuous processing of ferritic, martensitic, austenitic, and precipitation hardened stainless steels. EGU and EEG are recommended for chip breaking grooves, with EGU being the universal preferred option and EEG emphasizing chip breaking control.

AC6135M: A New Choice for Light Intermittent and Black Leather Processing

AC6135M adopts a new PVD coating, which balances wear resistance and chipping resistance in light intermittent processing and black skin processing. When unstable cutting occurs due to slight chipping, boundary defects, or black skin during processing, AC6135M can provide more stable performance. It is particularly suitable for light intermittent processing of austenitic stainless steel and duplex stainless steel. Recommend EGU and EEH for chip breaking grooves, with EGU being the universal preferred option and EEH used for stable intermittent turning.

AC6145M: A powerful tool for heavy intermittent processing

AC6145M adopts a combination of PVD coating and high toughness hard alloy substrate, which performs excellently in heavy intermittent processing. When severe chipping, rapid fracture, hot cracking, or cutting edge impact damage occurs during processing, AC6145M is the preferred solution. It is suitable for heavy intermittent cutting and unstable working conditions, especially for rough machining of austenitic stainless steel and duplex stainless steel. The recommended chip breaking grooves are EEH and EEM. EEH is used for stable heavy intermittent turning, while EEM is used to suppress rapid fracture.

Analysis of Coating Technology

The reason why the AC6000M series can maintain stability under different working conditions lies in the differentiated design of coating technology.

CVD coating architecture of AC6020M and AC6030M

AC6020M and AC6030M adopt CVD coating technology, and their coating structure includes four key design layers. The first layer is a surface smoothing treatment layer, which significantly suppresses adhesion and the resulting chipping by improving anti adhesion performance. The second layer is a high toughness aluminum oxide layer, providing stable and long tool life. 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. This coating combination enables AC6020M and AC6030M to effectively resist crescent wear and flank wear in continuous cutting and high-speed machining.

PVD coating architecture for AC6135M and AC6145M

AC6135M and AC6145M use TiAlBCN based multilayer coatings, providing higher wear resistance, anti chipping and anti adhesion properties. Its coating structure also includes four key design layers. The first layer is an anti adhesion layer, which uses TiCN based components with excellent lubricity to suppress adhesion and the resulting chipping. The second layer is a wear-resistant layer, which uses a proprietary high hardness TiAlN based multi-layer coating to significantly suppress crescent wear and rear blade wear. The third layer is the anti chipping layer, which uses ultrafine grained TiAlN based components with excellent toughness to suppress accidental chipping. The fourth layer is high adhesion technology, which enhances the adhesion strength of the coating and improves stability through special techniques. This coating combination enables AC6135M and AC6145M to effectively absorb impact energy during intermittent cutting and heavy intermittent machining, suppressing chipping and hot cracking.

Decision Tree for Chip Groove Selection and Troubleshooting

The AC6000M series offers a wide range of chip breaker options, including EEF, ESU, EEX, EUP, EEG, EGU, EEH, and EEM. Engineers can select models based on processing conditions and fault phenomena according to the following decision tree.

Main chip breaker: EGU and EEG

EGU is a universal preferred chip breaker with balanced chip control and wear resistance, suitable for most stainless steel turning conditions. EEG is a wear-resistant chip breaker that strikes a balance between wide range chip control and wear resistance, suitable for medium cutting. When the processing is stable and there are no special faults, EGU or EEG should be preferred.

Fault 1: Poor chip elongation or breakage

When chip elongation and poor chip breakage occur during small deep cutting, choose EEF chip breaking groove. EEF is designed specifically for precision machining and has excellent chip breaking ability at small cutting depths. If it is necessary to reduce cutting force at the same time, ESU chip breaker can be chosen, which has a small cutting depth and high feed design to suppress cutting resistance.

Fault 2: Rapid wear or insufficient sharpness of the cutting edge

When there is rapid wear and insufficient sharpness of the cutting edge during processing, choose EEX chip breaker groove. EEX adopts a standard shape, emphasizing the sharpness of cutting edges, suitable for light to medium cutting. If there is excessive resistance in areas with large cutting depth and high feed rate, choose EUP chip breaker groove, whose double positive angle shape can reduce cutting resistance.

Fault 3: Short tool life for high load machining

When the tool life is insufficient during high load machining, choose EEH chip breaker. EEH is designed specifically for intermittent machining, emphasizing machining stability and is the preferred recommendation for intermittent machining. If rapid fracture occurs, choose EEM chip breaker groove, which has the highest cutting edge strength with its large cutting depth and high feed design, balancing wear resistance and anti chipping performance.

Summary of Recommended Cutting Conditions

Based on the workpiece material and application conditions, the AC6000M series provides a recommended range of cutting conditions. The following is a summary of key materials.

Ferritic stainless steel (405, 410L, 430, etc.)

For precision machining and continuous cutting, it is recommended to use AC6020M with EEF/ESU, with a cutting depth of 0.020-0.079 inches, a feed rate of 0.002-0.010 IPR, and a speed of 558-984 SFM. Light intermittent and interrupted continuous recommended AC6030M with EEG/EGU/EEX, cutting depth of 0.039-0.157 inches, feed rate of 0.004-0.016 IPR, speed of 459-820 SFM. We recommend using AC6145M with EEH/EEM for heavy intermittent cutting, with a cutting depth of 0.059-0.236 inches, a feed rate of 0.010-0.024 IPR, and a speed of 328-525 SFM.

Martensitic stainless steel (410, 420J2, 440C, etc.)

For precision machining, it is recommended to use AC6020M in conjunction with EEF/ESU, with a speed of 394-787 SFM. Continuous and light intermittent recommended AC6030M with EEG/EGU/EEX, speed 328-656 SFM. Interruption and continuation recommendation: AC6135M with EGU/EEH, speed 262-591 SFM. We recommend using AC6145M in conjunction with EEH/EEM, with a speed of 197-459 SFM.

Austenitic stainless steel (304, 316, 321, etc.)

We recommend using AC6030M with EEF/ESU/EEX for precision machining, with speeds ranging from 394-787 SFM. Continuous and light intermittent recommended AC6135M with EEG/EGU, speed 328-656 SFM. Interruption and continuation recommendation: AC6135M with EGU/EEH, speed 262-591 SFM. We recommend using AC6145M in conjunction with EEH/EEM, with a speed of 197-459 SFM.

duplex stainless steel

We recommend using AC6030M with EEF/ESU/EEX for precision machining, with a speed of 328-591 SFM. Continuous and light intermittent recommended AC6135M with EEG/EGU, speed 262-525 SFM. Interruption continuation recommendation: AC6135M with EGU/EEH, speed 230-459 SFM. We recommend using AC6145M in conjunction with EEH/EEM for heavy interruptions, with speeds ranging from 164-394 SFM.

Precipitation hardening stainless steel

We recommend using AC6020M with EEF/ESU for precision machining, with a speed of 295-459 SFM. Continuous and light intermittent recommended AC6030M with EEG/EGU/EEX, speed 230-427 SFM. Interruption and continuation recommend AC6135M in combination with EGU/EEH, with a speed of 164-394 SFM. We recommend using AC6145M in conjunction with EEH/EEM for heavy interruptions, with speeds ranging from 131-328 SFM.

Practical case verification

The following case demonstrates the actual performance of the AC6000M series in the processing of different stainless steel parts.

316 component processing

Continuous machining using CNMG432EGU (AC6020M) with cutting parameters of vc=590 SFM, f=. 010 IPR, ap=. 118 inches, wet cutting. AC6020M exhibits excellent wear resistance, with a tool life three times that of conventional M20 tools. After processing 3 pieces, the cutting edge of AC6020M remained intact, while conventional tools showed significant wear after only processing 1 piece.

316L shell processing

Use SNMG433EGU (AC6020M) for continuous machining with cutting parameters of vc=590 SFM, f=. 010 IPR, ap=. 098 inches, wet cut. The excellent anti chipping performance of AC6020M has increased the tool life by 30%, and the cutting edge remains stable after processing 42 pieces, while conventional M20 tools only produce chipping after processing 31 pieces.

430 motorcycle component processing

Continuous machining using CNMG431EEF (AC6030M) with cutting parameters of vc=394 SFM, f=. 004 IPR, ap=. 031-0.059 inches, wet cutting. AC6030M provides stable machining surface quality, with tool life twice that of its competitor M30 product. It remains stable even after processing about 1200 pieces, while its competitor only processes about 580 pieces.

Casting stainless steel pump parts processing

Continuous machining was performed using CNMG432EEG (AC6030M) with cutting parameters of vc=328 SFM, f=. 012 IPR, ap=. 020 inches, wet cutting. AC6030M achieved double tool life at 2.5 times efficiency (VC increased from 197 to 328 SFM, f increased from. 008 to. 012 IPR), and the cutting edge remained intact after processing 2 pieces, while the competitor M30 product only experienced wear after processing 1 piece.

316L flange processing

Use CNMG432EGU (AC6135M) for machining, with cutting parameters of vc=492 SFM, f=. 010 IPR, ap=. 059 inches, wet cut. AC6135M suppresses crescent wear, and the tool life is 2.5 times that of the competitor M30 PVD product. After processing 5 pieces, the cutting edge remains stable, while the competitor only processes 2 pieces.

316L valve processing

Use CNMG432EEH (AC6145M) for intermittent machining, with cutting parameters of vc=361 SFM, f=. 006 IPR, ap=. 059 inches, wet cutting. AC6145M suppresses blade breakage, with a tool life 1.3 times that of the competing M40 PVD product. Even after processing 5 pieces, the cutting edge remains intact, while the competing product only processed 4 pieces and experienced blade breakage.

316L screw processing

Use CNMG432EGU (AC6145M) for intermittent machining, with cutting parameters of vc=361 SFM, f=. 006 IPR, ap=. 059 inches, wet cutting. AC6145M suppresses chipping and hot cracking, achieving stable machining. After processing, the cutting edge of AC6145M remained intact, while the competitor M30 PVD product showed obvious hot cracks and chipping.