20CrMnTi is a carburizing steel with a carbon content of 0.17%-0.24%. It has high hardenability. The workpiece after carburizing and quenching has a hard and wear-resistant surface and a 

tough core, and has high low-temperature impact toughness. It is widely used in parts such as gears, gear shafts, synchronizers, ball cages, tripod shafts, and cross shafts.

After carburizing and quenching, the hardness of 20CrMnTi carburizing steel is between HRC58-63. It not only has high hardness, but also has deformation problems during heat treatment. 

For small parts, the deformation is small and can be ignored. Some thin-walled parts or large-sized parts have large deformation after heat treatment, and the cutting allowance fluctuates, 

forming intermittent processing conditions, which has a great impact on processing tools.

In recent years, with the development of the machinery manufacturing industry, 20CrMnTi carburizing and quenching steel has also been widely used in various industries, which is also a 

challenge to the tool industry. It not only improves the impact resistance of CBN tools, and can withstand high hardness and strong intermittent cutting, but also adds new processes such as 

coating, chip breaker, polishing edge, positioning pit, etc. on the basis of CBN tools, while ensuring the quality of the workpiece being processed, it improves the tool life and production 

efficiency, thereby effectively helping to reduce the cost of manufacturing industry.

Among them, the D25 coating is light gray, which is a moderate material performance, suitable for continuous processing-medium intermittent processing, the D65 coating is golden yellow, 

suitable for ultra-high speed processing, continuous processing, and extended tool life, and the D75 coating is gray-brown, suitable for cutting at medium and low speeds and strong impact 

and strong intermittent processing.

The above three coated PCBN tools can better play the role of chemical barrier, thermal barrier and mechanical barrier for the tool during hard turning, so that the comprehensive performance 

of the tool can be fully exerted, the processing efficiency can be improved, and the tool life can be extended.